Hello, and welcome to Stuff to Blow Your Mind. My name is Joe McCormick, and today we are bringing you an episode from the Vault, an older episode of the show. This one is called do Ants Make Traps? It is about exactly that question, whether ants the insect build traps. This originally published January twentieth, twenty twenty two. Hope you enjoy.
Welcome to Stuff to Blow Your Mind, a production of iHeartRadio.
Hey, welcome to Stuff to Blow your Mind. My name is Robert Lamb.
And I'm Joe McCormick, and today we're going to be talking about traps. I think I've mentioned this in some Weird House Cinema episodes, but for some reason, ever since I was a little kid, I have always loved movie scenes where the protagonists build a trap to use against the villain or the monster. I remember, like Home Alone when I was a little kid, that whole sequence was great. It sort of expands to fill my whole childhood impression
of what the movie was. And if you go back and watch it as an adult, it's kind of weird that it's only like fifteen or twenty minutes of the runtime.
In Home Alone. Yeah, yeah, yeah, it does seem like that's the main thing I remember. Yeah, they the traps, the traps, and certainly people feel certain nostalgia for them.
My heart swells at the thought of a nail going into Daniel Stearn's foot. But also, yeah, I remember other ones, like you know, Arnold Schwarzenegger builds a bunch of traps and predator. But like, this wasn't just when I was a kid. It still works on me. I remember there was a sequence I just loved in the more recent horror movie It follows where the characters build a trap for the last year.
Yeah, that's right, that is very They have a very much a kind of home alones setup that they do there. Of course, it's not only the heroes that have traps. I always love a good villain trap as well, especially the trap door. And the trap door sequence is always a lot of fun, you know. Be it something like in Lynn Labyrinth. I love the trap when the trap door springs on our hero and that. But actually Tomorrow's Weird House Cinema also has a fun trap door sequence.
Oh yeah, so look forward to that. Well.
Yeah, on side of the protagonists getting through traps set for them, another one of my favorite movie sequences as a child was the beginning of Raiders of the Lost Art. Oh yeah, and when INDI's going through all the traps, something about it is just like, deep in the brain, it's very satisfying.
Wall to wall traps. Yeah, that's that's a great sequence as well. And all of these are great sequences in spite of the fact that when you when you can, when you really think long and hard about any of these scenarios, you know, the cracks definitely show would all of these traps still be working in this ancient ruin that Indiana Jones finds himself in. I don't know, it's a hard argument to make there, right.
How did the spring trap operate by you sticking your hand through a shaft of light when it was made like thousands of years ago?
Yeah, Or you know, if it's duke and predator, like, how does he how does he make this super powerful compound bow just in the space of a few hours on an afternoon in the jungle.
That's just standard survival training.
I mean, and all these other various e Wok traps that he builds didn't didn't you go to that camp? Did I build a bow like that at a cat camp. No, I think we sharpened sticks, you know, that would be that would be more believable. Right, he makes a spear, Yeah, to battle.
That's most of the way there.
Yeah, But you know, I think it probably speaks volumes for humans to be you know, to be said all of this about traps, and especially about you know, loving these cinematic treatments of traps, because because what are traps? Ultimately, very broadly speaking, they're clever, tactical and or technological innovations that level the playing field against predators, against prey, and even against fellow humans. Traps are the sort of things
that humans have been up to since prehistory. So of course we love traps, and of course we admire things like traps that we find in other species.
Right, So today we're going to be focusing on some allegations of insects with the ability to build traps, specifically ants that do things that may in fact be biological evolutions that allow them to trap prey. Now, there are some other animals that I think we could say more more clearly and famously create traps. I think the obvious example here would be spiders.
Yes, yes, spiders are the trap builders par excellence. You know, there are no finer trap builders in the animal Maybe you could make a case for human beings, but personally I'm not in favor of that. I think web building spiders especially are just such highly evolved trap masters. Every detail of their anatomy and behavior enhances their trapping ability, and the trap is very much an extension of their
own bodies in so many ways. And we've covered this, and we've covered spiders in general numerous times in the show before, and we'll likely keep coming back to them. But yeah, the spider, the spider is the trap maker. There's nothing else that the spider really does. Anything else it does the web building spider is going to do in close proximity to the web that it has built.
Yeah. Another example that's come up before, I think in our Sarlac episodes was the ant lion.
Yes. Yeah, this is a case where we have predatory larvae that in some species of antlon anyway, set up at the bottom of sand pits that they dig, ready to lack shout at anything that disturbs their grains and you know, ventures down into the trap. Again, not all ant lion species dig trap pits, but some of the most famous ones.
Do I remember. One of the great things we learned about the ant lion was that, like you say, it is the ones that make traps. It is just the larval period of their lifespan, their life cycle that they make the traps. Then they later metamorphosed into another form. But while they're in that larval stage, I think at least some of them never poop. So yeah, yeah, catching ants and eating them and just like waiting, and it's like if you had to wait until you turned eighteen to poop.
We'll go back and listen to that Sarlac episode if you'd like to hear more about the ant lion. There's also the species of creature known as the worm lion,
and this is unrelated to the ant lion. It's just a matter of convergent evolution that he ends up utilizing largely the exact same method again when it's a larva, though the pit itself in this case is generated via a slightly different method, so it digs its pit in a slightly different method, but it still consumes its prey in the same manner.
But for me, at least, if you ask me to make a list of non human animals, that make traps. I could obviously go spiders. I would have thought of the ant lion, maybe by association the worm lion. But there before I was reading up for this episode, I think I would have drawn a blank. I wouldn't know what to go to next.
Yeah, and part of it comes down to just how are you going to going to define a trap? For example, Here's here's an interesting potential example we can discuss that I read across read about when I was reading Gilbert Waldbauer's How Not to Be Eaten, which is largely about insects, but there's a part where the author is discussing the burrowing owl. So these are small birds native to the Great Plains in southern Florida. I think they're about the size of a robin. I'm to understand that, you know,
the small, little little guys. But they make their home in burrows that they did themselves. And one of the interesting things that they do in addition to this, if this wasn't you know interesting enough already, is the burrowing owl will scatter horse or cow dung around the entrance
to their burrows. And then, you know, times before European contact, this would have probably been bison dung, and the dung does seem to be important because if researchers remove the dung from the vicinity, the birds will just the bird will just go out and obtain more dung and place it in the vicinity. So it seems to be doing this intentionally. The theory is that they place the dung
to bait dung beetles. So they put the dung out, dung beetles come, And indeed researchers have been able to tell that the owls eat ten times more dung beetles than usual when the dung is out.
Ah. Well, this will in fact mirror one of the two examples of potential ant trap making that I want to talk about later.
Yeah, I mean it's but this is a great example. It's certainly clever. I like it. But it kind of forces us to ask the question of a trap, like what is a trap? Is it merely baiting a trap?
That is a good question, yeah, because and how much does the trap structure have to be separate from your body in order to recount as a constructed trap? And how much does it have to how much work does it have to do for you?
Yeah? And at what point does an animal's behavior stop being a trap and just become sneaky behavior, sneaky tactics, or simply ambush predation, because obviously there are plenty of examples of ambush predators on land and in the sea, and these include everything from well, the trap door spider for one, which I think is definitely a case of building because it's an ambush predator, but it builds a silk hinge trap door to aid in those ambushes.
Right, so the trapdoor hides it. I think you could count that as like infrastructure necessary to constitute a trap.
Yeah, yeah, I think that, Yeah, definitely with the trapdoor spider. But then you also have just various camouflage predators, including things like frogfish, praying mantis's, chameleons, and more, which are not building anything. They're not altering their environment, but they've evolved to look like a part of their environment and they have the you know, often tremendous abilities of camouflage that enable them to quickly ambush something that they want to eat.
Okay, that probably doesn't That doesn't really seem like a trap to me, because they're just evolved to look that way, and they they do the actual hunting themselves.
Right, And then of course you have various birds and cats and big cats even that are just very stealthy, that are just very good at not being observed by the things they want to kill. So I was reading a little bit about this in Douglas j Imlin's excellent book Animal Weapons that have referenced on the Show before, and he points out that creatures such as this generally depend on quote, a quick strike weapon that immediately incapacitates
its victim. And of course these bioweapons might be enhanced by special features, such as in various deep sea ambush predators a bioluminescent lure, which again is not something they have created or engineered out of their environment, but it is a part of their body. So when we come back to this idea that what it needs to be something that's built, it needs to be something that's engineered, or just a hole dug in the ground, even we come back to that same question, well, why don't we
find more of this? And I actually found an interesting paper title out there, Why are pitfall Traps So Rare in the Natural World? By G. D Ruxton and MH. Hansel, And it appeared in evolutionary ecology in two thousand and nine.
Interesting question.
Yeah, So the authors here point out that in order to lay a trap, you generally need either advanced cognitive powers as with humans obviously, or you need specialist self secreted materials as with spiders and cattisfly larvae, thing which the catasi fly larvae use that their their secretions to create a net like even meshed trap like a silk trap, in order to filter catch their prey.
That makes sense. So humans can create all kinds of traps because we have, you know, cognitive powers that allow us to imagine what could be done. How you know, other materials in the environment could be repurposed to passively ensnare or kill prey animals and spiders and stuff. That's just the trap you could almost say, is a part of their body. Even though the web is a built thing.
They revolved to secrete the silk for the web out of their bodies, and they have very instinctually driven behaviors for how they extrude that silk wear in what patterns.
Right, So, Ruxton and Hansel here ultimately point out that okay, we have the ant lion though, and of course the worm lion. These are exceptions to the rule. They make use of a pitfall trap, and so the authors ask why is this basic tactic not more common in the animal world? How hard is it, after all to dig a hole? They're easy, they're cheap, and yet you don't see this technique used by virtually anything outside of some
ant lions and worm lions. Apparently, the lack of more pitfall traps than nature was something of a mystery and remain something of a mystery.
Yeah, that is interesting, Okay, so it took me a second to get the distinction they're making. But they're saying that the ant lion and the wormline would be kind of an outlier because they don't have complex intelligence and imagination like humans, so they're not inventing traps with cognitive powers. But they also don't secrete a material that CONTs institutes
the basis of the trap like a spider. They're literally just building a trap out of the dead environment around of them by digging a conically shaped hole in such a pattern that ants get stuck in it when they fall down the side. And why is that so rare, because it would seem like that that should be a strategy that lots of animals could easily employ.
Right, Yeah, again, holes are ultimately easy to make, low energy. Why not? Why why? Why why is this cat not making a hole and using that as part of its hunting tactics?
So what are their thoughts on this, like, why would why wouldn't we see this more often?
Well, they proposed two speculative reasons for the lack of pitfall traps in nature. The first one is pitfall traps may require a specialist micro habitat. In other words, you can't do this just anywhere. Conditions have to be just right, such as you know, we can look at to the ant lions, they have to be kind of sandy conditions. You know, you have to have that kind of granular environment. So it's the kind of tactic that a potential trap builder would not necessarily be able to employ all over
the place. You would have to depend on again, on a specialist micro habitat.
I think I recall from our Sarlac episode where we had a segment about the ant lion that they needed the grains of soil to be of a particular size, like the sandy grains above or below a certain diameter threshold would not work very well for making the traps.
Yeah, yeah, Now the second point is that with the ant lion in particular, the trap target's small prey, and since they may be more functionally tied to their trap than spiders are, traps of this nature could serve as like basically a major bull's eye for potential predators. And indeed the main predators of ant lions and worm lions are birds who know what to look for.
That's a really good point. So by building a trap and then sitting in it and waiting for your prey to fall in, you were also usually going to be making a structure that makes it easy for things that want to eat you to define where you are. You know, they don't have to look too hard because you've made a big hole in the ground.
Right and and spiders just have a little more leeway with the situation. Now, I should point out Hansel also wrote an entire book which I'm going to reference here in a minute. He spends a lot of time in that book talking about spiders and how, you know, sometimes spider webs are very visible and other times they are not, and how that plays into the you know, the ultimate kind of complex relationship between spiders and the creatures that would eat spiders. But just thinking about this as the
trap being this conspicuous thing. This we actually see this in a lot of our fantastic trap fiction. You know that moment when the target of the clever cinematic trap, especially if it's laid by the protagonists, the enemy almost sets it off, right, like the predator almost triggers the trip line you've prepared. But then something happens, right the monster deduces that the trap is there, or it suspects that something is off.
Oh, and maybe even the presence of a trap is how the hero knows that they have stumbled across the bad guy's hideout.
Yeah. Yeah. It even reminds me a bit of our recent weird house selection, The Lift. This was the Killer Elevator movie, the Killer Elevator in this or I guess you were more specifically the weird biobrain that's been installed in the elevator shaft to power these elevators. It's kind of an obligate trap predator, but it's so tied to that environment that it's a little tricky, like it's not able to pull off every kill, and it's eventually destroyed by prey that is too clever for it.
Brilliant analogy. This is true. The killer elevator is an obligate trap predator.
I also have to point out, speaking of the Sarlac, is that recent Mandalorian episodes have also sort of played with this idea. Yeah, yeah, the Mighty Sarlac. The Startlack's pretty impressive, but they make it clear that even these great trap predators can be a soom by the mighty create dragon that lives in the deserts of Tatooine. So knowing you're there being you know, this identifiable organism in the sand, that can have a huge downside to it.
Now, I was trying to think of counterpoints to the idea that. Okay, so sitting at the bottom of a pitfall trap and waiting for prey to fall into you and then eating that that makes you vulnerable to predators that want to find you. Well, well, what if you just make pitfall traps and then you go away and then you know, leave them there and then come back like a human hunter might do, you know, leave a trap out in the woods and then come and see
what it collected lobster traps or something. But I can see downsides to that as well, because if it's just a pit trap, you could imagine that, well, something might fall in there, but then something else might eat it before you get to it, right, so, or it might you know, if you have to make these all over the place, you might spend a lot of energy going around from one to the other. So is that really all that much better than just hunting?
Well, and then it kind of comes back to this idea that the trap laid by an animal especially still requires the lethal mechanism, and in the case of the antlime, the legal lethal mechanism is itself. It is still essentially an ambush predator like again, like Emmilin says, quote a quick strike weapon that immediately incapacitates its victim.
Yeah, I can't believe I didn't think of that. That's, of course a good point. You have to find a way to kill the prey, right.
So I mentioned that that Henzel has a whole book that deals with with some of this a little bit, but just sort of the broader picture of animals building things. It's titled Animal Architecture, and I was reading through this a bit. He contends that we're not looking at traps when we're looking at cases of an animal baiting another animal, because traps are a kind of subset of animal architecture, an engineered space that aids in capture.
Okay, so by his metric here, what the burrowing owl does by leaving dung out around its nest and having this attract insects to it, that would not count as a trap because it is not a structure that in any way aids and capture. It just attracts prey to a site.
Oh, by the way, I want to also, speaking of the burrowing owl again, I want to throw in that while some burrowing owls do build their own burrows, they're also burrowing owls that acquire the burrows of other creatures. Anyway, I want to read this quote from Hansel here. I think he puts it rather well concerning the animal architecture and traps quote. Whereas a house can just be a barrier between the builder and the outside world, a trap
has a dynamic relationship between itself and the prey. The prey needs to approach the trap in a particular orientation to it, and then needs to be restrained by it. Traps are therefore more complex than homes and need to be more precisely engineered, and then he goes on to point out the quote among the vertebrates, trap builders were
apparently absent until the recent history of man. Now he cites human mental capacity once more for the construction of such traps, noting quote, Virtually all non human trap builders use self secreted materials, and the capture principle they adopt is the net. Exceptions are simple in design and operation, as well as rare, and then he goes on to specifically mention antlions, worm lions, and larval diptra.
But anyway, a large takeaway here is that trap building is not as widespread in the animal kingdom as you
might expect. Humans make a lot of traps. There are some very specialized animals, especially some invertebrates, that use traps made of materials that they secrete from their own bodies, but generally, trap building is not a very widespread hunting strategy among animals of planet Earth, in which case it would be very interesting to find examples of animals such as ants, that make traps in order to get their nutrition. And I guess that's a good segue to what I
to the main focus of today's episode. Which was a couple of examples I came across of ants that do something that could be interpreted as building traps as a hunting strategy.
Yeah, and I mean it would make sense that we might find something like this in the ant world because ants are masters of construction, they alter their environment, they're capable of practicing agriculture. They as we've discussed in previous episodes of the show, they engage in complex conflicts that we might well compare to warfare. They can solve problems there.
I mean, the list goes on and on. Ants are amazing as of course, as the now Light e O. Wilson was fond of reminding us, you know, ants, there are incredible creatures that we've covered them numerous times in the show before, we're covering today, and I'm sure we'll cover them again exactly.
So the first example I want to talk about I found so interesting, and this one also has some interesting differences in interpretations I came across. But just to start
with the basic report. I was reading about this in a paper published in Nature in the year two thousand and five by land Jan Pascal, Jean Solano, Julian Irole, Bruno Corbara and Jerome Oreville called arboreal ants build traps to capture prey, and also as a supplement to the paper in Nature, I was reading a summary feature that was also in Nature by NoREL Tawi, published in April two thousand and five, called Amazonian ants ambush prey. So here's the deal. There's a plant in the Amazon called
Hertella phisofera, or maybe Phisophora physo phora. I'm going to try to say fizzof so these here Tella plants. Plants in this genus are woody trees or shrubs. I've seen them called both trees and shrubs, but they're if you're trying to picture them as a tree, you should be imagining a small tree, so woody stems, but not like
you know, sky high. Plants in this genus are found in the tropics across multiple continents, but their diversity is concentrated around the Amazon, and they typically have flowers that are pollinated by butterflies. And this one species in particular, here Tella physophera, is what the authors of the paper call an ant plant. This is a plant species that is known to have a specific biological relationship with a species of ant and these can be found throughout the world.
There are very common mutualisms, or you know, various kinds of symbiotic relationships between ant colonies and the trees or plants they inhabit. Now, this plant in particular has a relationtionship with the arboreal ant alomeras decim articulatus, and they live on the body of the plant, forming colony centers in what the authors of the paper call leaf pouches. They are these little bulb looking things that can usually be found at the places where the branches split into leaves.
They look like these it's kind of hard to describe them. They're just these little like green lobes or orbs, and apparently the ants like to get inside those and make nests in there.
Now. Already, one of the things that's that I'm reminded of is the idea of like a specialist micro habitat. And if you have a situation where a plant is the home to the ants, that they have this ant plant relationship in place, you know that the plant itself is kind of the environment, it's kind of the micro habitat that the ant is the master off.
That's exactly right. But the interesting thing is of course, ants being builders, some ants will form complex, you know, dugout colonies in the ground or other types of interesting engineered environments. They can also engineer the microhabitat of the surface of a plant, and that's what we're going to be talking about in this case. Oh and I should say that the colonies that were looked at in this two thousand and five paper were from French Guyana in
northern South America. But so what you find in these plants that are occupied by their familiar ant species is that along the stems of the host plant, the ants will build what the authors of this paper call galleried structures, or sometimes they just say galleries. It's kind of hard to describe exactly what this is, but imagine a kind of platform built out over the surface of the stem of the plant, and it's a platform that the ants
can crawl underneath. And then this platform has a kind of spongy texture, almost as if fits or honeycomb texture. It's aligned with all these holes in the platform that the ants can crawl in and out through. Generally the holes are just slightly larger than the diameter of one of the worker ants heads. So through these platforms raised above the stem of the plant. Ants crawl underneath them, but then crawl up and up and down, in and out through the holes in the platform.
Yeah, it is kind of difficult to describe it because it is so different from something that that humans would for the most part build, you know, by virtue of the ants being far more mobile and sort of living in a more three dimensional space than human beings tend to.
By the way, these are great to look up, probably unless you suffer from trip to phobia, in which case stay far away.
Yeah, if you're if you're freaked out by things like lotus pods and random holes and things, yeah, you might. You might want to avoid this particular Google image search.
Now, how do the ants build these galleries, Well, they apparently make them by cutting off tricombs from the stems of the plant. Tricombs is a word that comes from the Greek word for hares. These are small, little fibery appendages that poke out from the surface of a plant. You've probably seen lots of plants before that have little hairy things all over the stem or the leaves. Those are tricombs, and they do look a lot like hares.
So the worker ants will move along the stem of a Hairtella physophera plant, clearing away the tricombs, and then, just to read from the language used in the paper here, quote then using uncut tricombes as pillars, they build the galley's vault by binding cut tricombs together with a compound that they regurgitate later. This structure is reinforced by the mycelium of a complex of sooty mold species that has
been manipulated by the ants. Fungal growth starts around the holes and then spreads rapidly to the rest of the structure. So I think you heard that right. So these ants build their galleries along the stem of the plant by cutting the hairs off of the plant where they live, then using those hairs as building materials, along with their own barf as a kind of mortar, and then holding everything together by seating it with mold or fungus that
they farm. So they have a kind of agricultural project for farming fungal rebar that they use to reinforce the galleries that they build. And in quotes given to the press, I've seen the authors of this study compare this composite material to fiberglass.
Wow, Yeah, that does seem like a good comparison. Oh man, I mean, it's just so amazing that it's not just like this physical act, but they're actually yeah, seating it with with this this mold. Oh man, they're kind they're build it, but they're also kind of growing it.
Be amazing, and they tend to it as it grows. So I wanted to read another section from the study where they talk about the evidence that the ants are actively tending the fungus as it reinforces these structures. They say, quote, we noted that the stems of thirty four young seedlings, which had not yet developed leaf pouches, did not bear fungus. Nine saplings raised in a greenhouse in the absence of alomeras.
That's the ants developed leaf pouches but never bore fungus. However, fifteen saplings raised in the presence of ants bore mycelia, whose development was limited to the galleries. When we eliminated the associated ants from five of the fifteen, the fungus on the galleries grew into a disorganized structure, and none of the nine new stems that developed bore any fungus at all. Okay, so the fungus is only showing up on the plant when the ants are there on the plant.
And if you take the ants away from the plant after they've been using the fungus to reinforce their their galleries, the fungus kind of grows out of control in what they call a disorganized structure. But with the ants still there, it stays nice and tightly formed around the holes in the galleries. So they're tending their garden. It's like a living I don't know, it's like if you had to have maintenance workers constantly sort of gardening and tending to the fungus that held up your skyscrapers.
Wow.
But here's where we start getting to the trapping. So the authors of this study say that they noticed that sometimes larger insects would become immobilized on the surface of the galleries. So you got these these spongy surfaces, ants crawling underneath them, and sometimes like a locust or a butterfly, some bigger insect lands on the gallery and then it gets stuck. What's going on here, Well, they started to investigate whether the galleries could be functioning as a type
of trap. And here's what they say about how the ambush works quote. Our observations revealed that Alomiras workers hide in the galleries with their heads just under the holes, mandibles wide open, seemingly waiting for an insect to land. To kill the insect, they grasp its free legs, antennae, or wings and move in and out of the holes in opposite directions until the prey is progressively stretched against
the gallery and swarms of workers can sting it. The ants then slide the prey over the top of the gallery, again moving in and out of the holes, but this time in the same direction. They move it slowly towards a leaf pouch where they carve it up. Oh and then once they get to one of these population centers of the colony, you know, the these nest sites in the leaf pouches, they tend to feed bits of protein from the insect to their young.
Well, yeah, this is amazing and suitably brutal for the world of ants. So this, this larger creature lands or walks on to the structure. You know, they're reaching out of holes to pull it straight down, and then they transfer it to a place where they can carve it up.
Right. So yeah, there's no sentimentality in the world of ants, they're just like, okay, this is edible, It's time to get to butcher in But anyway, these observations reveal this fascinating three way interaction between the plant, the fungus, and the ant all sort of living together in this this three way life cycle. Essentially that apparently serves the purpose of creating a trap to get larger insects. You know these Oh I don't think I mentioned, but the Alamiris
decim articulatus ants are very small. It's a structure that allows these tiny ants apparently to capture kill and butcher much much larger prey.
All right, And of course the plant out of all of this gets some slight mutilation from the ants, but is protected from larger insects that would otherwise no on it and do more harm to it than just creating an interesting lattice work out of its body.
Presumably, I mean, I think often there is such a relationship going on. The insect also provides a benefit to the plant somehow, though in the sources I was reading it wasn't clear to me exactly if it's known what the major benefit provided by the ants is, but I would guess that's right, that they're probably protecting the plant from herbivore large herbivore insects that would chew its leaves down or something, But I don't know for sure. I gotta admit right.
And then of course we also have to always realize that in the natural world the line between parasitism and symbiosis is sometimes a bit thin. These are not relationships that are governed by strict contracts, so you might see a little bit of push and pull over the course of evolutionary history.
Ants will take whatever they can get.
You're right, so you be careful about entering into a bargain with the ants.
But on the other side of all this, I wanted to come back on it because I found a book where the trap interpretation of these structures has been challenged. And in fact, this book was by somebody who's come up on the on I think episodes we did about ants last year, the biologist Mark W. Moffatt. Yes, yes, yeah, So he has a book called Adventures among Ants that was that came out in twenty ten University of California Press.
And in this book I found a section where Moffatt argues that the trap interpretation of these structures built by alameiras decim articulatis is in fact a misinterpretation. Now I'm not sure he's right about this, but I do want to explain what he claims, so it's a bit of background.
In the section of the book directly preceding this, Moffatt has been talking about his observations of various species of army ants on raiding parties to forage for food and also on defensive patrols to protect the colony and the rating column from threats, and one of his observations in this preceding section is how difficult it is sometimes to tell the difference between these two behaviors and how easily
one bleeds into the other. So, according to Demoffitt, for most army ants, their defensive attacks on a creature that is perceived to be threatening the raiding column can quickly turn into a foraging raid in itself. So if the threat is killed, it is pretty much immediately chopped up into pieces and carried away as food. So it's kind of like if you imagine every monster movie ended with the heroes butchering and eating the monster after they finally defeated it.
Well, we do see that sometimes. In fact, that occurs in the Mandalorian but the case of the Great Dragon. But but yeah, we should see more consumption of the d of dragons and monsters and so forth. Use every part of the monster be responsible.
Well, I don't know. I mean that's you know, humans are different than ants. I mean, ants are not going to let anything go to waste. Humans, after you've fought a monster, you might just want to have nothing to do with it. To each species their own. But anyway, so from here, Moffat moves on to describing the ant I've been talking about Elimeris decim articulatus, and he's describing its living situation. The one distinction he makes I couldn't
find out what was what was the disconnect here? But he said, you remember how I said that the ants build these gallery structures out of tricombes cut from the plants, a little plant hairs, mixed with their own regurgitation or vomit, and then lined with the mycelium of the fungus that they cultivate. Mofatt describes it the same way, but he mentions feces rather than vomit. And I don't know who's
right there. But anyway, Moffatt gives a few reasons that he had doubts about the generally accepted interpretation of this structure as a trap, specifically as a trap, because he says a trap implies that, for example, a locust landing on the ant gallery would not have landed there if
it saw the ants. The trap would be performing the function of hiding the ants, so you know, they're hidden beneath the vault of the gallery, so that the prey insect feels it's safe enough to land and then they jump out and grab it.
Okay, this would be in keeping with say the trapdoor spider would probably be a great example of this.
Yeah, yeah, I think that's comparable. That's how it would function as a trap. But Moffitt writes that he thinks this is unlikely because he doubts that grasshoppers would really be able to notice the tiny workers of this ant species anyway, quote particularly in mid leap, or that they would be able to change course in mid leap after
noticing them. So he was a little iffy on that, like, I'm not sure that the trap would really serve much purpose if it's supposed to be hiding the ants from the prey animal, because these are insects that are much larger than the ants anyway.
Right, So he's saying, basically saying like this might be if this was a trap, which he doesn't think it is, it would be a preposterous trap, an unnecessary trap. And while again we love unnecessarily complex and preposterous traps in our cinema, we're not talking about cinema here. We're talking about.
Evolution, yeah, and sufficiency.
Yeah yeah. Things need to be ruthlessly efficient, and if it's not ruthlessly efficient, it is going to change or go away.
But anyway, those are his suspicions, so he decided to put them to the test. So he tells a story of that he was studying colonies of this ant in the wild in Ecuador, and he put together a test to interrogate the trap interpretation. So to read from the section of Moffitt's book where he describes this test, he says, quote, hung a mosquito net over a plant with a thriving alomeras colony, added one hundred grasshoppers and katie diids, and
sat inside for the next five mornings. An unusual case of using a mosquito net to keep insects in instead of out. Even after the grasshoppers settled down, they were indiscriminate in their movements, hopping from where the ants hid under the structures to where ants strolled in full view, to where there were no ants at all. When they landed among the ants, even on the structures, they got away unhurt. Certainly, if the structures served as traps, they
were inefficient ones. So he's saying in his observations here, he's seeing very little correlation between the structures and the hunting behaviors of the ants or the behaviors of the prey insects. So what purpose does he believed the galleries are serving. Well, he points out that the galleries tend to run along the stems of the tree, connecting each nest pouch to another nest mouch, and they quote contain
a highway of workers commuting from nest to nest. And then he points out that other insects, including other ant species, do sometimes build various types of physical covers over their trails, which are generally interpreted to be defensive in nature. For example, some marauder and driver ants have been observed to build soil covers over their trails, So could that be what's going on in this case? Could these galleries that the ants build actually be defensive in nature? Another strike here?
According to Moffat, he observed that the workers at his study site did not actually sit and wait at the holes in these galleries, as you might expect them to do if they were planning an ambush. He says that when conditions were normal, so like if the colony is not in an agitated state, things are just sort of going along normally. Most of the gaps in the gallery structures were unoccupied. But he says this chain when there
appeared to be some kind of threat to the colony. Quote, after a day of pulling grasshoppers from my hair, I noticed interlopers of another ant, a species of Fidolei or big headed ant, climbing the plant to pin down a wounded grasshopper missed by the Alomiras. Upon the arrival of the fidole ants, the Alomiras workers began to guard each
of the several dozen entrances to their arcade. And that's the arcade, is what he's calling the things that the other authors called the galleries the several dozen entrances to their arcade nearest the commotion caused by the intruders. These guards, aided by nest mates roaming the arcade surface, also caught
and killed one fidoli and carried it off. So, based on these observations, moffittt argues that the galleries are more likely defensive to protect trails of workers moving from one leaf pouch to the other, but that when something attacks or threatens the colony, the workers quickly shift their behavior from travel to defense, and then they occupy the holes
and start biting violently at anything that comes near. And of course, if they are able to immobilize an attacker or not necessarily an attacker, if they're able to immobilize whatever it is that put them on the defense, they immediately shift rolls again and turn that threat into food and begin butchering it for the colony again, to cook the monster, so to speak.
So we might be better to think of these as defensive fortifications, kind of like to use like a medieval castle or fortress scenario. It's kind of like the various crinolations and murder holes and arrow slits, except with the added point that in this case the occupants of the castle or fortress would eat those that they killed defending it.
Right, That's what Moffatt argues, And so to finish up his section, he says in the end, quote in this way the organization of a super organism, referring to ants. There because I think you can make the argument that, you know, an ant colony might be best understood as one organism rather than many. It is a super organism composed of many different bodies, he says it quote can be more responsive than the tissues in a body. Trail Bound workers can shift seamlessly in their behavior from transport
to protection to predation. It's as if one's liver could change function when the heart is incapacitated and pump blood. So obviously I don't know who's right here. Moffatt's book is more than ten years old at this point, and most of the things I read about this ant species alomeris decim articulatas still describe the galleries as ambush traps.
And I'm not sure which interpretation is correct, but I do think either way, Moffatt makes a very interesting point about the fluidity of function when it comes to ant behavior. How you know one moment's enemy is the next moment's lunch.
Right, Yeah, Like the ant colony is not just trying to do one thing. It has a lot of objectives and it has again this fluidity of function. Whereas it's far easier to look at a web building spider and know what's up. You know that the web is its purpose, the web is kind of its sole, and there's no question about why it constructed the web.
I guess. Also, this raises another question about what counts as a quote trap because assuming for a second that Moffatt's interpretation is correct, I don't know it is, But if he's right that these structures are primarily to defend the ant trails, but then when something when a threat presents itself, they turn around and use the holes in the galleries as murder holes and then eat whatever they
can immobilize, does that count as a trap? Like how specialized does a structure have to be for the purpose of catching prey in order to be thought of as a trap, Because you can imagine other examples where an animal builds a structure that's primary defensive in some way, it's more like the home from the example you talked about at the beginning in that book. You know, it's
a barrier between you and the outside world. Yet it has some kind of feature that like another animal or something could get stuck on or some you know, it somehow allows you to sometimes opportunistically harvest from the structure and then eat from it. And does that count as a trap?
Now? I haven't seen this movie in a very long time, but but I think there might be something comparable in Home Alone too, am I right? Oh?
Lost in New York, the one with Tim Curry?
Oh? What Tim Curry's in that one?
Oh? Yeah, I think he plays a He plays a snooty bell hop or something.
Okay, that sounds about right.
Yeah, but yeah, I think the Actually, we were trying to figure this out what this was, and Seth's just chimed in to let us know he was right. The house where he builds the traps and Home Alone two is a house that's like under renovation, so it already has feature Like, all the traps don't have to be in from scratch. There are already features of the house. I don't remember exactly what they are, but there are things that are dangerous about it already.
Okay, yeah, yeah.
But I wanted to talk about my second example of ants potentially doing something that you could interpret as a trap ok, and this one also involves using foreign materials around the nest. So the second example was described in a paper that I was reading published in twenty nineteen in the journal Ecological Entomology by Innacio Gomez Diego, Santiago Ricardo Campos, and Heraldo Vasconcelos. It was called why do
fight oly oxyops ants place feathers around their nests? And I also got some additional information from reading an article about the study published in Scientific American by Joshua rapp Learn in November twenty nineteen. But here's the deal. So there is this species of ant called Fidolei oxyops. We were already talking about some fidoli ants in the last example because the remember the fidoli ants invaded the tree and then they got kind of butchered by the alomiras ants.
But fidoli ants are a genus known as the big head ants, and this species, in particular, fidoli Oxyops, is native to South American savannahs. So these would be you know, grasslands ants. Sometimes they appear to do something pretty weird. They collect feathers and place them around the entrance of their nests. So, if you imagine the nest is buried, the entrance is basically a hole in the ground, and then you might just find feathers all around the holes,
scattered around on the ground outside the hole. That's weird. It might make it look like the ants ate a live chicken or something, but that is not what happened. They appear to collect the feathers and put them there.
Yeah, it kind of looks like there's a hole in the ground and like a bird was sucked down that hole, and this is these are the cartoonish remnants of that incident.
I thought the same thing. Yeah, I was like, hmmm, pop and then just puff of feathers they settle around it. But no, that is not what has happened. The ants put the feathers there. Strange. So this paper published in twenty nineteen in Ecological Entomology, it claims that these feathers function as bait to attract prey animals, which then tumble into the nest entrance as if it were a pit trap. And the Scientific American article actually reports a bit of
the background on the paper. It says that the studies. First author in Nacio Gomez, is an ecologist at the Federal University of Visosa in Brazil, and while walking around city parks and his college campus, he noticed examples of these ant nest entrances with feathers all around him. Apparently this had been observed, and also I was looking at
another paper about this ant species, fidally oxyops. This one was by Diego asis at All from twenty twenty one, and this paper said that in addition to feathers, there will sometimes be other objects around these entrances, including shells, flower pedals, and seeds. But this study in particular was focusing on the feathers, and so he noticed these feathers around the entrances and he wondered what was the deal
with this. Apparently this had been observed before, and there were already a couple of untested hypotheses in the scientific literature about what the feathers were doing there. One idea was that the feathers could collect do in arid regions, so they would help provide the ants with water in the mornings, and the other idea was that some of the feathers could serve as lures, attracting prey to the nest,
and so the twenty nineteen study tested both. In one experiment, the researchers supplied the ant colonies with water soaked cotton balls, so made sure they had access to plenty of water, but the ants in these cases preferred to collect feathers anyway. It did not seem like access to water played any role in their desire to collect feathers, and this could be evidence that the feathers were not primarily for collecting water. But another test was designed to see if feathers scattered
on the ground would attract prey. So they tested this with artificial traps that were made to resemble the nest entrances of these ants, and the team found that if you put out a trap and scatter feathers around it, for some reason, it will tend to trap more just sort of wanderers, you know, arthropods that are out on the ground, than traps without feathers, And so interesting question why would they do that. Why would a hole in the ground surrounded by feathers get more bugs to fall
into it. It's not known, but Gomez suggests that maybe it's something about the smell of the feathers, something about the visual appearance. Maybe a quote he gives to the Scientific American article, he says, just in general, soil insects are quote very curious, So maybe putting an unusual item around the entrance to the nest will just tend to get wandering bugs to walk up to it and see
if it's something of use to them. But I think this would not count just as baiting the way the burrowing owl example would with the cow dung or the bison dung, because in this case it's not just to get the insects close to the nest. In this case, the actual nest entrances, basically holes in the ground, function quite well as pit traps because once the prey insect falls in, they have difficulty climbing back out, and the
ants will rather quickly grab and butcher them. Now, this is clearly not the only way this ant species has to acquire prey. Fidolioxyops do lead the nest to acquire prey.
They forage like other ant species. But it's possible that using the nest as a pit trap and surrounding it with feathers as some kind of evolved behavior for luring more insects into the hole that helps the colony supplement their diet during especially times of the year, such as the dry season in this region when prey is more scarce, harder to come by.
So they wouldn't be obligate trap builders. They would they would be sort of they would have like a trap business on the side. I guess you would say.
Yes, if the trap interpretation is correct, it seems like this would be a supplemental role in getting extra food to them, extra diet diversity, especially in times when they're they're going to be getting less in their foraging or maybe when they're doing less foraging.
Okay, yeah, because they're you know, again they're altering their immediate environment anyway. There and then again, a whole like this is not a huge energy investment.
Is already part of the nest.
Yeah, already part of the nest. I guess the question is coming back to those those reasons that were put forth earlier that we don't see more pit traps. Does this would this make the the ant population more visible to potential predators?
Yeah?
I mean maybe so, maybe not. Maybe maybe the animals that would be interested in eating the ants already would be able to detect their presence. And then again also the ants have more capabilities than that one little larva at the bottom of a small pit. You know, we're not dealing with one organism. We're dealing with this, uh, this entire colony of organisms that that kind of behave as a single organism.
Yeah, obviously I don't know what all the you know, the cost benefit analysis of this evolutionary calculus would be. But but yeah, there must be some reason why by having your ant nest a as a pit trap and this environment for this ant is is not such a it's not such a danger that it outweighs the benefit of getting some bugs to fall in as free meals. But I also like this because it's like by house analogy.
It's like if your entire house was just like below the ground and the entrance to the house was a spike pit trap like a tiger trap. Yeah, just waited for things to fall in and be like, oh bonus, here's dinner, and you always and you had the lures, you had the feathers all around. I don't know what that would be in the human example, you put just cotton candy around the around the trap that you come in through.
Well, this is certainly another fascinating example. Yeah, and I love how both present the possibility of ants building traps.
But since they are ants, like it's it's not that cut and dry, like, ants have a complexity all their own, so you can't really look at them in the same way that you would look at a single solitary spider or certainly even you know, the human example, Like what we do with traps and how we think about traps is a rather different scenario compared to anything, you know, anything that we're seeing in several of these animal examples.
Yeah, well, I guess that does it for ant traps on my end.
But yeah, well this was fun. Who knows what the future will hold. Perhaps there'll be more exciting studies coming out of the world of ant research. I mean, it's it's highly possible. I mean, we're still we're still making significant discoveries about ant species and what they're up to.
There are frontiers of ants you couldn't even dream of.
There are ant traps that we don't even know about yet because they haven't been sprung on us.
When you fall into them. You go through the two thousand and one stargate and in the room with the French furniture.
You know, we've never watched an ant movie for a weird house cinema. I wonder if we should at some point.
Oh, I have for years been looking at the cover of a Blu ray at Videodrome called Phase four. It's a picture of a hand with some ants. I know it involves ants. I don't know anything else.
I guess the question I would have, especially after talking about ants like this again, is are we looking at thinking about movies that have a giant ant in them and have encounters with various giant ants, or is it truly about the ants as this kind of super organism And I like the latter.
Yeah.
Yeah, though, maybe having a giant sized ant is kind of a way through our fantastic fiction that we think about super organisms. So it's kind of like, yes, the ants are small, but they work together and they're able to do great things. So we just think of like a giant ant. That's like just one way of contemplating what they're capable of. So the next time ant movies come back, if you're out there thinking about resurrecting the giant ant movie, consider having them like tear people apart.
Things like that. You know, crawling out of windows, pulling people taunt against the sides of a building and then transferring them up to the rooftop and tearing them to pieces.
Nice final processing.
Yes, all right, well we're gonna gohe and close out this episode here, but we'd love to hear from everybody out there about traps, traps and movies, Traps in the human world, traps in the animal world. Is there is there some corner of this topic you'd like for us to explore more in the future. Let us know we
would love to hear from you. If you would like to listen to other episodes of Stuff to Blow Your Mind, you will find them in the Stuff to Blow Your Mind podcast feed Core episodes on Tuesdays and Thursdays, listener mail on Monday's short form artifact on Wednesdays. On Friday, we do Weird House Cinema. That's our time to set aside most serious concerns and just look at a strange film. As always, you can also get to us rather quickly by going to Stuff to Blow your Mind dot com.
Huge Things, So as always to our excellent audio producer Seth Nicholas Johnson. If you would like to get in touch with us with back on this episode or any other, to suggest a topic for the future, just to say hello. You can email us at contact and Stuff to Blow Your Mind dot com.
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