Do Snakes Have Tails?

Transcript

ERIC: From the Museum of Science in Boston, this is Pulsar, a podcast where we search for answers to the most puzzling questions we've ever gotten from our visitors. I'm your host, Eric, and I've been working with snakes the museum for almost a decade, and one of the best questions I've ever been asked about them happened on my very first time standing in the exhibit halls with a snake on my arm: do snakes have tails? And my answer at that time was: I have no idea. Joining me once again on the podcast to solve this mystery is Becca from our programs team, who can regularly be seen on stage at the museum with snakes of all shapes and sizes. Hi, Becca.

BECCA: Hi, Eric. Thanks for having me joining you today.

ERIC: So our question today really got me when I first tried to answer it, because it seems pretty obvious that snakes don't have tails. They're just a head and a long body. And at the same time, it seems pretty obvious that snakes do have tails. They're essentially one big long tail with eyes and a mouth. So which is it?

BECCA: They do have tails, but most of their body is in fact, just sort of a bunch of ribs. Snakes have a lot of vertebrae, between 104 and 150 in their main part of their body. And they only have about 10 to 205 in their tail. Now, there's a huge difference between some of these numbers. And that's because there are many different shapes and sizes of snakes, some incredibly small and some as long as 30 feet. So they have a lot of different types of bones.

ERIC: Yeah, and the smallest one is, like, the size of a quarter or something, right?

BECCA: Yeah, there's a very small one, and it's not even an inch long. And then the reticulated python getting up to about 30 feet long.

ERIC: So this question, when I got it, really sent me into a sort of existential reptile crisis, because I started thinking, do snakes have lungs, or a stomach? They have to, they're animals, but how do they fit inside that long noodle body? And the answer is that it's just all kind of crammed in there. And their organs serve the same function as ours, but they're just different shapes to fit inside.

BECCA: Absolutely, their organs do the same thing that ours do. They're just kind of longer and they stretch throughout more of their body. Our ribcage is pretty compact. And so we can fit all of our organs inside it kind of nicely. They're not super squished. But in a snake, those organs just ended up being really long, and they all just kind of get squished in there. And you know what, it works for them.

ERIC: Yeah. And if you did a snake X-ray, you'd see, you know, organs, and then they stop, and then there's a definite tail. So yes, snakes do have tails. And we get a couple other questions really commonly, and one is, is that snake venomous? And many snakes are venomous, they use that venom to weaken or kill their prey before they eat it. But a lot of the snakes and the ones that we work with, for the most part, are not venomous. They're constrictors. So why don't you tell us what constriction is in terms of a snake?

BECCA: Sure. So you're absolutely right, we do not handle venomous snakes on stage. But we do have a lot of snakes that are constrictors. And in order for these snakes to eat their food, they have to squeeze them, constrict whatever animal it is that they're trying to eat, and that will cut off some of the blood supply. And ultimately, that is how they can kill their food in order to eat it. Sounds pretty intense. And a lot of people worry about us holding these constrictors on stage. But fortunately, snakes are pretty smart about what they can and can't eat. And all of the snakes that we have are far too small to eat a human. So we are actually really safe when we're holding them. They're not constricting us.

ERIC: Yeah, I always say, you know, a snake five feet long wrapped around my arm a couple of times, when people say, is it squeezing you? Is it constricting you? I say, first of all, no, it's just kind of treating me like a tree branch. It's just hanging on, so it doesn't fall off. And second of all, snakes are strong. And if that snake decided to constrict my arm, you would know it because I would react. They have really strong muscles, and great adaptations for being able to constrict their prey. And one of my favorite things about doing animal shows is that even though you do them forever, you can always learn new things about them. And I just read a paper that showed that boa constrictors can feel their prey's heartbeat. And the reason for that is that squeezing costs energy. So if you want to squeeze your prey until it's not alive anymore, you don't want to squeeze too hard and waste energy, but you don't want to squeeze not hard enough and have it take too long. So if a boa constrictor can sense their prey's heartbeat, they know exactly when to stop squeezing, and when it's time for dinner.

BECCA: That's super cool. I know we have a boa constrictor here that I work with a lot and I kind of love the idea that he might be able to sense that. I don't know. I think it's really cool.

ERIC: Yeah, maybe just listening to your heartbeat hanging on your arm but still knowing you're not food?

BECCA: I'm definitely still not food for him.

ERIC: So we also get a lot of question about snakes' senses, and especially from people who are seeing the snake up close. Why do they always stick their tongues out?

BECCA: I love this question. And so many people wonder this, but snakes can actually use their tongue to help them smell. What they do is they stick their tongue out, they swish it around a little bit. And by doing that, they're actually picking up air molecules. And in those air molecules are the smells, and they're able to then detect different scents in the air. By bringing those air molecules into their mouth, and to something called their Jacobson's Organ, that's sort of a scent processing center inside their mouth. Now, they can still use their nostrils to smell a little bit, but mostly that's for breathing, they often do a lot of their catching of sense with their tongue. And that's how they're able to process it really well. They don't really need to taste like we do, they don't have that developed a sense where they taste different food, really, they're going to eat anything that they can. So instead, they use their tongue to help them smell.

ERIC: And when you see them up close, they are constantly sticking their tongue out, they are smelling their environment, almost every second, it seems like some of our snakes are just flicking their tongue in and out.

BECCA: I think it's cool, because then you know that they're really kind of taking in all of their environment with both their eyes and also with their sense of smell by using their tongue.

ERIC: And another thing people ask about is: so snakes have heat vision, right? And that's true for some snakes, they have heat pits that can actually sense the body heat of prey to be able to pick it up better.

BECCA: Yes, some snakes have heat pits. In general, pretty much all pythons, some boas, and all vipers have heat pits. And these are different holes kind of in the front of their face, that have all of these heat sensing nerves. And this is so cool, because that means that they can see heat patterns of kind of anything around. So if they're looking for a mammal, that mammal is going to be warmer than kind of everything around it. So they would see that that mammal, even if it was hiding, kind of stood out among the rest of the background. Now we're not entirely sure exactly what this looks like in a snake. Because we've never been a snake to see this.

ERIC: Can't see through a snake's eyes.

BECCA: Exactly. But we do know that they can sense this. Now, even if some snakes don't have heat pits, like some boas don't. We think that they might still have heat sensing scales, so they can also probably do this same thing. That's amazing. Because these animals can hunt so well at night, just by being able to sense heat.

ERIC: It makes sense that if you're hunting at night, and there's not a lot of light, that you would need some other way to find it sneak up on your prey.

BECCA: Yeah, and this is a very cool way to do it.

ERIC: To sort of wrap up, a lot of people ask us, what do you do if you see a snake in the wild? How do you handle that question?

BECCA: I love this question too, because honestly, one of my favorite things to do whenever I'm on a hike or walking around in the woods is to try and find a snake. But I will not pick up a snake in the wild because I don't want to make them uncomfortable or get them scared. I'll just admire them from a distance and then maybe take some pictures and then walk along. It's kind of like if you see any animal in the wild, you shouldn't just go right up to it or try and pick it up or try and poke it or something you don't want to bother them because that's them just trying to survive and live. But I definitely welcome people to try and find animals if you're quiet enough walking through the woods, and you might be able to hear the rustle of leaves. And there could be a small garter snake or a water snake if you're around here in New England, and just look at how they're moving and admire the way that they can get around without arms or legs.

ERIC: Becca, thanks so much for talking all about snakes, and their awesome adaptations.

BECCA: Thank you, Eric. This was fun.

ERIC: To meet our snakes in person, you can always visit the Live Animal Care Center at the Museum of Science, as well as catch our daily live animal presentations. Check mos.org for details. And while you're at home, you can watch what happened when our ball python laid eggs in our Sparks of Science video series. Until next time, keep asking questions.

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