True Facts: The Crazy Defenses of Butterflies and Moths

The adult form of insects in the order Lepidoptera, the butterflies, and the mothis, are some of the most beautiful insects in the world. But come on, they're ridiculous. Just look at them. To get to this point, they've had to go through a baby phase as a sort of above-ground, slow-moving worm thing. And then they just hang out for a couple weeks in a sleeping bag dingleberry. So they've had plenty of time to plan, and this is what they turn into. I mean, it's not like being in nature is a walk in the park. Well, I guess it is. But my point is, it's dangerous out there for a butterfly. Jerry, that's a fish. Oh, dang. And that bird's a dick. My point is, everything's trying to eat you, and that's the body you're working with? Come on, it's like being in the middle of a battlefield and someone's dancing around in a kimono. Just look at the way they fly. It's like a drunk person trying to find the bathroom in an Ikea. But don't fall for it. It's a ruse. Lepidopterans are the perfect killing machines. Jerry, that's not true. Well, I don't care if you saw it on Reddit. We talked about this. Do your job, Jerry. Anyway, butterflies and moths have two pairs of wings, one in front and one in back. These wings, in comparison to their bodies, are much larger and broader than those of other flying animals. Now, being lightweight with huge flappers means that they can take advantage of some of the fluid properties of air. First off, they don't flap that often, around 10 times a second. Compare that to the 200 times a second of a bee, for example. With each stroke, the edges of their wings create swirls of air that resemble smoke rings. On the downstroke, these vortex rings move down and away from the body, which results in vertical lift. But on the upstroke, the rings move away more horizontally, which causes the butterfly to move forward. So as the butterfly flies, it leaves behind a trail of these vortex rings, as it alternates between lift and propulsion. But there's an additional trick going on here. These wings are razor sharp and... People get killed to death? Really, Jerry? Just stop it. These wings are quite floppy floppy. And if you're paying attention, you can see that on the upstroke, the wings bend in a way that causes the front edges to come together first. This seal creates a pocket of air that's squeezed out like a fart from under a duvet, as the rest of the wings close on each other. And that air bubble is shot right out through the center of a vortex ring, just like that fart was initially shot out. And this creates even more forward propulsion. Now when they fly backwards, they change the angle of their body, so the upstroke creates lift and the downstroke moves them horizontal. So when you see butterflies flip-flapping all over the place, like the flying equivalent of a mosh pit, they're doing that on purpose. They can fly in a freaking straight line if they want to. They do that crazy flying schtick to **** with the birds that want to eat them. It's a defensive strategy. Float like a butterfly, it stings when I pee sort of thing. Here, you know how some butterflies are toxic to birds, right? Not my personal favorite form of defense, by the way. Yeah, that's right, I taste like crap. Eat me, bird. Oh, shit, you are. Here, for example, is a blue jay puking right after eating a monarch. Showed him. Anyway, the poisonous ones often have brightly colored wings, so at least the birds can learn to stay away after a couple bouts of food poisoning. These toxic ones also tend to fly slower and straighter. It's like another signal to the birds not to **** with them. Now, non-toxic, delicious butterflies will often mimic the colors and patterns of toxic butterflies to get some of that protection. And some of these mimicking butterflies are polymorphic, which means they can come in a number of different forms. Sometimes each one of those forms mimics a different toxic butterfly, but it goes beyond that. Females of the species Papiliopolitus come in a few different forms. This one, the top one, it's mating, mimics a toxic butterfly, while this form mimics a non-toxic male. Here's the kicker. When it mimics the toxic butterfly, it doesn't just mimic its colors, it mimics how it flies, flying slower and straighter. And that's the thing. These beautiful insects are bullshit artists, and it all comes back to those wings. I mean, I know they look like they're made from tissue paper that got wet over top a child's marker drawing, but that's more bullshit. They're incredibly sophisticated. Don't get me started. Well, I guess I already have. The whole thing kicks off in the sleeping bag theme. First, the basic shape of the wing is formed by these two membranes that sandwich together around veins. The veins both add some structure, but also carry the butterfly's version of blood, butterblood. Once that's on its way, a series of overlapping scales begin to form on the outside surface, and each one of those scales is anchored into its own little socket. As these scales form, you can see colors begin to emerge, transforming them into the scary clowns of the insect world. Jerry, you're afraid of butterflies. They're not dangerous. No, clowns are. I mean, butterflies aren't. You can see that it's not just one pattern that forms, but rather a series of patterns that overlay one another. Some of these colors, like these browns and blacks, are made from pigments like melanin, which we have in our skin. Pigments work by absorbing certain wavelengths of light and reflecting others. Your bright blue t-shirt absorbs all the wavelengths except the bluish ones, which are reflected back to your eyes. The scales of the butterfly can have some pigments in them, but so can the membranes underneath them. Here is Cyproeta stellinis. On the right, all of its scales have been removed from the wing. The remaining green is formed from a liquid pigment in the membrane that can stain a piece of paper if you touch it. But this is a bit unusual. Many of the brightest and most impressive colors on butterfly wings don't come from pigments or anything that would stain a piece of paper that touched them. Instead, the colors are made from the architecture of the scales themselves. If you zoom in, you can see that the scales are made of these ridges, and the ridges can come in a number of different three-dimensional shapes. In some, there's a place for little pockets of pigment to hang out, but in others there's no pigment at all. Instead, there are these structures called lamellae, which are just the right size and shape to take advantage of some of the strange properties of light. As light hits one of these, a certain amount is reflected back off the surface, and some light just passes right through. But depending on how thick these are, some wavelengths are reflected off the back surface. Now these two sources of reflected light interact with each other, sometimes canceling each other out, but sometimes amplifying each other to create an intense color. Whatever light passed on through often hits another one of these lamellae, and then another, reflecting back even more of a certain wavelength. That's how this blue morpho, for example, gets such a vivid blue. If you change the angle that the light hits these structures, the wavelengths interfere with each other differently, and that's why some butterflies shimmer and appear iridescent as they move. This is different from pigments, which reflect the same wavelength, regardless of which way you look at them. Oh look, that one's laying babies! But often, these butterfly colors are the combination of both pigments and the structural colors made by the lamellae. That blue morpho from before has a layer of black pigment underneath, which absorbs the light that passed through and wasn't reflected. But there's another species of morpho that has the reflective scales, but not the black pigment, and the wings appear this bluish-opal white. If you want to learn more about the physics of how butterfly wings get their color, or the computer science behind things like artificial intelligence, or even how a toilet works, well Brilliant.org is a free and easy way to learn about math, science, and computer science. I've been looking at the course on how LLMs, or Large Language Models, work. It shows you the building blocks behind how artificial intelligence can generate text from prompts, like give me a 40-word book review of Moby Dick as read by Cookie Monster. You learn about some of the core concepts, like tokenization, where text is split into smaller units, or temperature, which isn't about heat, but rather how random the output will be. There's thousands of lessons tailored to your interests and skill level, and they're interactive, so you can go at your own pace and get some help if you need it. To try everything that Brilliant has to offer, free for a full 30 days, visit Brilliant.org slash ZeFrank, or click on the link in the description. The first 200 of you will get 20% off Brilliant's annual premium subscription, and you'll be supporting a brand that helps make this show possible. Try Brilliant today. Where were we? Oh, right. Now, if you've got the ability to do all that with color, you know you're going to get creative. These tiny little patches of cells sometimes form on the wing, and they release proteins that cause the surrounding scales to create different sorts of pigments. This is how butterfly eye spots are formed. And I get it. You turn a corner and see one of these, you might shit your pants. This one, not so much. More of a sad vibe. And then, come on. I mean, this one's just adorable. I don't want to run away, I want to get closer to it. And then, of course, there's too much of a good thing. But why stop at just eyes? I mean, you could tattoo snake heads on your shoulders. Who's going to want to **** with you then? Now, if you're not feeling flamboyant, you can take a more subtle approach and blend into the background. Or be see-through. Sort of. I mean, come on, that looks just like a dead leaf, standing upright on a living leaf. Shh. But if a predator sees through your little disguise, you're not fucked yet. Some butterflies and mothas that are drab or camouflaged have bright colors on the insides of their wings. So if they get found out, they can buy some time with a little razzle-dazzle. And that shit works. And the science hippies know, because they **** with the chickens. Chicken thinks it's in for a nice meal, and then, nope. Reacts like a sane person would if they picked out a black licorice jellybean. If you're one of those weirdos that likes them, I don't want to hear it. It's an abomination. Now, if all of this doesn't work, and you're about to get a bite taken out of you, you still have some control over what part gets bit. Those long things on the back wings of the swallowtail, for example, seem to be effective at drawing an attack. And in fact, the veins on those back segments are weaker, to allow for a piece to rip off a bit more easily. And that's not a bad result. Butterflies and mothis can often fly just fine, missing a back wing or two. The back wings, it turns out, help more in dodging and weaving than they do with the actual flying. And that's why some of them look a bit ridden hard and put away wit. I'm bringing that phrase back. Now, mothis that are active at night sometimes have these really long tails. In the dark, they can't really use colors and patterns to the same defensive effect, because the bats that hunt them use sound instead of vision to hunt. Shooom. Having a really long tail can confuse the hell out of a bat, or at least get it to do minimal damage. But when you're getting hunted by something that uses sound, there's other tricks you can use to confuse the hunter. Some mothis have scales that can absorb sound, making them invisible. Or inaudible. I don't know. But another way to go is make more sound. Most mothis have exceptional hearing and can sense when a bat is closing in. And some use special structures that can create clicking sounds to jam the bat's sonar. Sometimes that involves scales on the moth's abdomen, or in this case, the genital valve. You can try this at home. Now there's a species of moth that lost its ability to hear, so it can't hear the bat's coming. You know what it does? It uses part of its wingbeat to make a sound, so it can make bat-confusing noise all the time. And so the bats try to catch things that don't exist. And that is how the Lepidopterans do. Haven't done that for a while, have we, Jerry? Oh, and also, it's not floats like a butterfly it stings when I pee, Jerry. It's a bee. No, the bee isn't peeing, Jerry. It's stinging. Do you understand? No, the bee isn't the reason it stings while- What do you mean, how did it get up there? No one's peeing, Jerry. Well, of course it would hurt, Jetman. That's beside the point. That's what the bee said. I don't get it.