Science Friday - A Halloween Monster Mashup, And A Spooky Lakes Tour

Episode Date: October 31, 2025

For Halloween, we bring you an ode to three quintessentially creepy creatures: bats, arachnids, and snakes. First, bat researcher Elena Tena joins Host Flora Lichtman to describe tracking the greater noctule bat in flight and learning that it can feed on migratory birds. Then, arachnologist Paula Cushing describes the camel spider, which is neither a camel nor a spider. And herpetologist Sara Ruane highlights one of her favorite snakes, the tiger keelback, which is both venomous and poisonous. Plus, what makes a lake spooky? A pond possessed? Flora talks with Geo Rutherford, creator of the Spooky Lake Month series on TikTok and Instagram, to learn about some of the spookiest, most mysterious lakes on the planet. Guests:Dr. Elena Tena is the national coordinator for the Spanish Bat Atlas project.Dr. Paula Cushing is senior curator of invertebrate zoology at the Denver Museum of Nature and Science in Denver, Colorado. Dr. Sara Ruane is curator of herpetology at the Field Museum in Chicago, Illinois. Geo Rutherford is the author of Spooky Lakes: 25 Strange and Mysterious Lakes That Dot Our Planet and the creator of Spooky Lake content TiKTok and Instagram. You can find her @geodesaurus. Transcripts for each episode are available within 1-3 days at sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

I'm Flora Lixman, and you're listening to Science Friday. Happy Halloween. On today's podcast, a monster mashup, an ode to three quintessentially creepy creatures, bats, spiders, and snakes. They're kind of scary, too. I mean, I'll grab one because I'm desperate to collect them for our research, but even I am a little bit reluctant. Starting with a bat tail that will haunt your nightmares, particularly if you are a Robin. The greater noctool bat is Europe's largest bat species with a wingspan of about a foot and a half. And here to tell us more is Dr. Elena Tena, national coordinator for the Spanish Bat Atlas Project.

Elena, welcome to Science Friday and tell us about this bat. Thank you very much, Flora. Very nice to be here. I really like that we talk about bats here with how. Halloween because people associated right with fear and these kind of things, but they're not dangers and they're impressive and really exciting. And I think it's very cool to talk today about the greater knockpool bat and what is doing. This is the first time we just recorded how the greater knock full bat capture and eat this bus while they're migrating. And I think

the results are really, really impressive. Okay, let's just take a step back in case people missed it. These are bats that eat migrating birds. Exactly. Like, they are mainly insectivores. Here in Spain and in Europe, all the bats we have, they are insectivores. But in the case of the greater noctal bats, sometimes opportunistically, it can eat some beds during migration. So, first of all, we knew that because we found some feathers on the poops of the bats. And the thing is that when we did the DNA of the pieces of the, of the, of the, of the, of the, The bats, we realized that they were eating more than 30 different species of birds. And all of these birds, they were migratory birds.

Oh, you're on a long trip and then a bat just takes you out. So you found feathers in the bat poop. And then your team, do I have this right, put data recorders on the back of some of these bats? Yeah, what we did, it was in a collaboration with Orchuz University in Denmark. What they had, it was these biologars that are very tiny. they have accelerometer to register movement. It has also an altimeter to register an attitude, and it has what is the most important for us, a microphone that is recording the sounds.

So this was the way we could prove how the bat was interacting with the bird, because we were recording all the audios. So we have like all the noise of the floppings, of the windbeat of the bat. We had the echoes of the bat, and we also have like, when we have, like, when the bad was shouting, the echo going forward and backward. So we could know if the bat was, for example, intercepting a prey, we had like the echo bat. And even what is most exciting, it was when it was approaching to a prey.

We knew if it was successful or not, because we could listen to the chewing, that it was one of the most impressive things. Chewing. Yeah, the chewing. Like, you could hear like, you know. So it was very,

nice, like, to listen to the bats interacting in the night, you know, and most of the times there were insects. So it was a fast-tuning, you know, like, but we were thinking, would we know if a bud is hunting a bird, would we listen to the, we would be listening to the bird because we didn't know if the bird would be a screaming or something like that, you know. Yeah, so tell me, did this happen? Did you catch on, on audio? Yeah, so this was the most, for my academic career, it was like the most exciting I have ever done because we were looking like through many data of audios and suddenly in one of these audios, we hear like first of all very strong flakings and then we suddenly hear like,

and after a few years ago, yeah, and that's the bird. Yeah, it was like 21 distress calls and after that, like the bird, shut the cut up. So the chirps stop. Yeah, exactly. And that's it. That's the kill. Yeah.

So it was just a few seconds. That is the moment that the bat is capturing the bird until the bat is killing the bud. So after that, we could listen to 23 minutes of chewing, of massacation. Wait, 23 minutes of chewing? Yeah, exactly. But for me, like the most important thing is when we overlap. this with the accelerometer and the altimeter. So we could understand better how the bat was doing.

Our hypothesis was that the greater local bats, they were flying up very high to try to detect the birds while they are flying up in high attitudes. And when we saw the attitude like the bat was flying more than one kilometer high, and suddenly, like in three minutes, it was falling down almost close to the ground. And the bat is chasing the birds for almost three minutes. yeah like one close to each other like diving downwards vertically till the bat captures the the bird almost close to the ground and when it captures the bird the body's flying normally like

it's not getting down with the weight of the bird that this is something like for physics like really a challenge wait so is it eating on the go for the 23 minutes it's chewing is it in flight it is flying normally, completely normally, eating the pet. So that was also, like, as we were saying at first, like, these species, the bats are amazing and they're really impressive, and we still have many things to know about them. Dr. Elena Tena is the national coordinator for the Spanish Bat Atlas Project. Thanks for joining me today, and happy Halloween. Thanks, the same for you too.

Up next in our Fright Fest, Arachnids. They're one of the most species diverse groups of creatures on the planet with well over 100,000 species. Compare that to about 6,600 species of mammals. Here to tell us about one arachnid that really belongs in your goody bag is Dr. Paula Cushing, a senior curator of invertebrate zoology at the Denver Museum of Nature and Science in Denver, Colorado. Paula, welcome to Science Friday. Hey, thanks so much, Flora. It's good to be on. You're an expert on the camel spider, which is neither.

a camel nor a spider. Correct. Introduce us to this creature. Scientists are very nerdy people. We like to organize life on earth into different taxonomic categories, kingdom, phyel and class order, family, genus, species. And spiders and other arachnids are in the kingdom onomalia, phylum arthropoda, class arachnida. And within that class, there's all these different orders. So spiders are in the order arrainiis and camel spiders are in the order solofuge. So they're a completely different group of arachnids. They do not have venom like spiders do. They do not have silk glands like spiders do. They are very active, cursorial predators, meaning that they're running around on the planet's surface, and they run fast, they run long, and they are voracious predators. When they find an insect,

sulfugids will just tear it apart, and then they will vomit out digestive enzymes like most arachnids do, and those digestive enzymes break up the tissue of the body, and then they slurp it in. But they will eat and eat. We've read reports of sulfuges that have been kept in captivity that they eat so much that they burst. They basically eat themselves to death. Because I think in the natural environments where they're found, they're very common in Zurich, harsh, dry, desert-like habitats where.

Food may not be super abundant, so they're opportunistic predators. And that means that in nature, you know, if they can get a good meal once a week, they're doing pretty well. If they can get a few insects a night to eat, they're doing pretty well. So if you bring them into the lab and just throw crickets at them, I think they're just overwhelmed. They're like, me and I have just died and gone to heaven, and then they literally do dry. I can relate. I've been there with a pint of ice cream. Sometimes it's hard. It's hard to resist. I think I might be able to resist the overeating crickets, but still, you know.

Besides eating themselves to the point of explosion, do they have any other claims to fame? So with most arachnids, spiders and scorpions and daddy long legs, they have bursts of activity. They can run in short bursts and then they're sort of running out of oxygen. They have to kind of stop and regain their composure to a certain extent. That's not the case with camel spiders. Camel spiders, I had a colleague, Yael Lubin, who in the Negeb desert in Israel, she followed a camel spider for over an hour to see how long it could run without stopping. And she ran out of energy before it did. So the camel spider just kept running. So they have this really interesting metabolic capacity that allows them to just move and move and move and move and hunt them. They're kind of scary, too. I mean, I'll grab one because I'm desperate to collect them for our research, but even I am a little bit reluctant. This is the perfect Halloween arachnid to know about. Thank you. Yes, it is. Spiders are, they're no big deal. But man, soul fugitives, they scare me even.

A lot of people are spider averse. Why do you think that is? You know, I've traveled a lot all over the world. And what I think is that in parts of the world where we keep nature at bay, we, we, we, we, We plant non-native grasses in our yards, and we really love our asphalt. And nature to us is something up in the mountains, something far away, something you go visit. And it's not part of our daily lives. Then any organism that is really distant from human lifestyle, from human understanding, is something kind of scary. Because when I travel to places in the world where they may live, where the jungle is, coming right up to their homes where nature is more a part of the everyday life. They don't bat

an eye when I say I study spiders. The spiders and the organisms that I study don't seem to elicit that kind of fear response. It's when we distance ourselves from nature that we start to see this fear factor. And I think that's part of it. I think also that on a visceral level, people understand that spiders are predators. And so there's this natural reaction to be a little bit wary of a predator, be it a tiny little spider that you could stomp on, or be it a shark, or be a lion. You know, there's this, oh, these are predators, and we need to be careful around these predators. Dr. Paula Cushing is a senior curator of invertebrate zoology at the Denver Museum of Nature and Science in Denver, Colorado. Thank you, Paula. You're welcome for us. It's great to talk to you.

From eight legs to no legs. Next up in our Halloween horror show are snakes. And here to share a tale of Slythery Delight is Dr. Sarah Ruan, curator of herpetology at the Field Museum in Chicago. Sarah, welcome and tell us about the keelback snake. Thank you so much for having me today, Flora. So this is the genus Rep Dilthus. And these snakes are related to the garter snakes and water snakes. We have right here in North America.

And so they're very common in places they live, which is primarily across Asia, including Russia, especially in Southeast Asia, as well as countries. such as Japan. And these snakes, they're sort of unassuming looking. They're maybe two or three heat long, so they're not huge. Like any villain, you know? Yeah, exactly, right? Unassuming, you'd have no idea what really lurks behind their unassuming countenance. What's so cool about these snakes is when people talk about snakes, they often say, oh, is that snake poisonous? What they really mean when they say that is, is that snake venomous? Because the majority of snakes that are medically

important to us are snakes that have venom, which means they are injecting it into your circulatory system. They're injecting a substance, a toxin. When people talk about poison, what that really entails is something you ingest. So venom and poison really aren't the same thing. And the majority of snakes that we talk about are going to be venomous. So cobras, rattles snakes, all the different kinds of vipers. Okay, so venomous means they're going to bite you and get poison in you, that they use this. And poisonous means if you barbecued one, it would make you sick. Yes, exactly. So the thing about Rob Jophis, about the keelbacks, especially this one called the tiger keelback, is that it is both venomous. And it is simultaneously one of the only snakes that is actually

poisonous as well. It's both. It's both. It's a double whammy. Yeah. Exactly. Exactly. Exactly right. Okay. And why do they have this trait? So what is so cool about this snake isn't just that it is poisonous. It's how did it become poisonous? So what this snake is able to do is it loves to eat frogs and toads. And toads themselves are often poisonous. They produce all these different kinds of toxins, often called bufotoxins. It makes it really hard for a lot of animals to eat them. And so if you think about, oh, we've got now marine or cane toads potentially in Florida bopping around. People will say, oh, my dog grabbed this toad, and now it's foaming at the mouth from chewing on it. And that is what will happen. So eating something that's poisonous like a toad would also give you a pretty bad time.

And it's bad for a lot of species of snakes. A lot of snakes are not able to handle these bufotoxins. Rabdofus has evolved to be able to handle this. But not only can they eat these toads, they take the toxins and the toads, the poison, and they sequester them in their own bodies. And this is called kleptotoxism. Oh, my God, I love that. I love that word. Cleptooxism. I know some kleptotoxic people.

Right. They're feeding off of other people's murder. So these snakes, these tiger keelbacks, eat these toads. And not only do they get a good meal out of it, they're also getting this extra benefit of taking the toxins from the toad and storing them in these glands on the side of their necks called knuckle glands, or nukal glands, depending on how you want to pronounce it. And these snakes not only then are poisonous for something to eat, these tiger keelbacks can sort of shoot that poison out of the side of their necks at things that are trying to get them,

right? And if it gets into someone's eyes, a human's eyes, for example, it's going to cause a little bit of temporary blindness and certainly some unpleasantness. So they're a triple threat. Yes. Yes. So they can also lead. It's not just eating them and it's not just what's in their mouth, which is known to occasionally cause fatalities. It's also they can shoot this out of the side of their necks in some really fancy way that is pretty surprising because this is not something most snakes.

I'm not sure actually any other snakes are able to do that particular trick. This is like my new favorite animal. So thank you. I know. It's really, really cool. One of these other things I wanted to mention in talking about keelbacks is so this tiger keelback super, super special. But it turns out that these snakes, a lot of them are eating frogs and toads. There's over 30 species of revdophis.

Another species that's found a little bit further south, but India, some other parts of China, surrounding countries. is another one that instead of eating frogs and toads, it primarily eats earthworms, which seems like no big deal. Except that not only does it sometimes eat earthworms, it also sometimes eats firefly larva, which themselves produce a different kind of toxin that these keelbacks are able to sequester and use the same way that the tiger keelback uses toad toxins. So there's more than one way to skin a cat when it comes to being a klepto toxic snake. You can clepto all around the animal kingdom, it sounds like. That is right.

You don't need to bother producing your own toxins because you can get them from somewhere else for free, simultaneously getting a meal at the same time. Oh, I love it. Dr. Sarah Ruan is curator of herpetology at the Field Museum in Chicago. Thanks again for joining me today. Thank you. Coming up after the break, a visit to some of the strangest, spookyest lakes on the planet.

A lot of times lakes are in our back. And we're so familiar with them that it kind of makes them feel, you know, like a neighbor that has secrets. The nerdy nightmare you didn't know you needed. Spooky Lakes. But what makes a lake spooky? A pond possessed. Here to Captain this ghost ship is Geo Rutherford, the creator of the wildly popular and wildly nerdy Spooky Lake Month series on TikTok and Instagram.

If you have missed this Eddie of the internet, don't worry. We are bringing spooky lakes to your shores. Geo, welcome to Science Friday. Yes, hello. Thanks for having me. What makes a lake spooky? Ooh, I always feel like that's such a good question because I think it's important for people outside of Spooky Lake Month to realize that it's not really about ghosts or ghouls or conspiracy theories or true crime. But Spooky Lakes is actually about science and history, the natural world being spooky all by herself and environmental disasters. Give me some examples of spooky criteria.

Oh, for sure. I mean, shipwrecks are very spooky. Places that are toxic to swim in or dangerous to swim in are spooky. So like a river that can suck you beneath the surface or a mining runoff that has turned the water orange. Those can all qualify as a spooky lake topic. Love it. And scientifically speaking, why lakes? Do you think lakes are especially spooky?

Well, I started with lakes. I did my entire thesis on the Great Lakes. And so I started with a fascination for lakes. And that process kind of led me to realizing that there's a lot of weird lakes in the world. And I don't think that they've really gotten their love when it comes to social media or even books. I feel like people are just not thinking about lakes. So there was kind of an opening there that I started to fill with Spooky Lake Month. And I think they're overlooked.

They're definitely underappreciated. And I think that lakes are in a lot of ways more spooky. than a lot of other water bodies because they have like this element of the unknown. Like you don't know what's beneath the surface, whether something's kind of being preserved at the bottom. And you'll never really know about it. There's something inaccessible about it. Kind of similar to the ocean. But I think because a lot of times lakes are in our backyards and we're so familiar with them that it kind of makes them feel, you know, like a neighbor that has secrets.

Which is the ultimate spooky plot line? For sure. Well, I think we should dip our feet in. Will you tell us the tale of one of your favorite Spookiest Lakes? And then maybe I know you rate them too. So maybe we can compare ratings after. Well, I think that the one to always start with, the one that I do every year, like there's been enough content that I've done this lake every year for spooky lake month, usually on Halloween. And that's Lake Superior, which a lot of us here in North America are familiar with and have a great love for. And that's because we as people have been traveling on Lake Superior for centuries, and we have this giant shipping system set up in the Great Lakes because of the St. Lawrence

Seaway. And because of that, over 10,000 people have died in Lake Superior. And there's some 400 shipwrecks at the bottom, which might not be the most. No, that seems like a lot of people. Yeah, it's a lot of And I mean, the Great Lakes in general have around 10,000 shipwrecks total. So Lake Superior doesn't have the most of all the shipwrecks. But because she's so cold and so giant, and she's known for these specific November gales where the water is warm enough that it kind of stirs up storms more aggressively in the more northern part of the Great Lakes. She's just vicious and terrifying. And she's taken out ships. And the other thing about the Great Lakes in general is that they, you know, the water is freshwater, so everything freezes and there's ice kind of coating these giant ships.

And the waves are much closer together so they can be really difficult for even these giant freighters to kind of handle, which is how you end up with shipwrecks like the Edmund Fitzgerald. But my favorite shipwark to talk about is actually the SS Camloops, which went down around Isle Royale in the early 1900s. But something else about Lake Superior that most people might not understand is that. that because it's extremely cold freshwater that doesn't have a lot of bacteria or activity at the bottom, like it's kind of lacking a little bit of oxygen. Bodies can be preserved for an extremely long time in the bottom of the lake. And so the SS Camloops has a permanent resident. His name is Old Whitey.

He lives in the boiler room. I'm not sure about that name, but okay. He's one of the crew members that has never left the ship. since he died. And his body is perfectly intact because of a chemical reaction called suponification, where the minerals and the cold freshwater interact with human skin and kind of create this coating of soap across the entire body. And that creates this like hard shell that protects it from decomposition. And so there are bodies like that across all of Lake Superior, but you can actually go and visit old Whitey in the SS Camloops boiler room.

You can visit the corpse of this person who worked on the ship that's now covered in a white soapy substance to look like an actual ghost. Yeah. And if you are swimming in the boiler room with him, then the movement of your fins kind of moves him. And so there's like tales of old whitey kind of following you around the boiler room in the SS cam loops. moves moves him like not just like flutters his soapy hair but like picks him up that's the that's the legend okay so should we give our ratings yeah what do you think it's like a 10 out of 10 how does it get spookier than that yeah i i definitely agree with you on that one lake superior is always a 10 out of 10 Spookies. Okay, give us one more lake that we can, yeah, put in our pocket, put in our

goodie bag. Another lake that I've managed to do multiple videos on because it's just so fantastic and strange is Lake Bycall, which is the oldest and the deepest lake in the world. And just for context, Lake Superior is around 10,000 years old. But Lake Bycall is 25 million years old. It's on a Rift Valley where the earth is pulling apart. So even though it has 300 rivers like bringing sediment into it, because it's pulling apart, the sediment is just kind of filling in that gap in the earth. And this is in Russia? This is in Russia in like an isolated part of Siberia, which is good because it's an extremely special lake that needs protection. And so it's good that it's kind of isolated. It's by far the deepest freshwater lake in the world. And because of that, it's a very much.

been around for a long time and it has this unique environment, 80% of the species that live in Lake Baikal are endemic to that lake, which means they can't be found anywhere else. The lake has special sponges and special amphipods. My favorite fish is called the Golem Yonka, which is an oily fish that lives in the deepest parts of the lake and it's cannibalistic. But I also really love the Baikal Nurpa, which is the world's only exclusively freshwater seal. that lives at Lake Baikal. And it's been there for some 2 million years. And no scientists really understand how it got there to be in this freshwater lake in the middle of Siberia.

Wow, a freshwater seal. I didn't even know there was a freshwater seal. There's a couple more. There's this wonderful little seal in Finland and a seals in Alaska and Canada. But there's only a few in the world that are kind of considered freshwater. Well, I feel like the seal deducts spooky. points personally because seals are cute, you know? Are there other things we should know about this lake before we render a verdict? Oh, for sure. I mean, I won't get into all the details of all

the amazing Russian history, but they also say that the Tsar's gold is at the bottom of the lake because of different points in history where there was like war and people had to go across Russia and escape. And then it resulted in lots of people kind of ending up dying on the lake and the gold falling to the bottom. Also, if you're wondering, I know you're thinking about this, how would you die in Lake Baikal? You know, we know how you'll- I was thinking about that, that, exactly. We know how you die in Lake Superior. You've preserved for eternity, but you wouldn't be preserved in Lake Baikal, even though it's incredibly deep and incredibly cold. Instead, you'd be eaten alive by their giant amphipods, or not alive. If you'd be eaten dead by the giant amphipods,

they would feast on your corpse. They're like the largest freshwater air. amphipods of the world. They're as big as your hand and there are, you know, millions of them in the lake and they would be very excited if you drop down to the bottom. It's like a human cocktail for them. Yeah. You should Google a picture of them that I call amphipod. They're so creepy looking. They kind of look like a crab almost. Like they're giant. And there are amphipods in other like lakes of the world, but they're much smaller. So the ones here have like evolved to be gigantic and I love them. Okay. Well, so, okay, so I'm going to do my calculation now. We've got on the one hand, gold and a seal. So, again, I think that deducts points. And then on the other hand, we have giant crustaceans that are going to eat you up and a cannibalistic fish. So I'm going to give it a six and a half. We usually give it nine out of ten on, on. I'm a tough grab, but I love the seal. You know, it's really, for me, it's a six.

all about the seal. Usually during Spooky Lake Month, I don't focus on the seal. I'm like, don't pay attention to the cute seal guys. Like, let's talk about being eaten by amphipods. You know, like we said at the top, lakes don't always get a lot of love, right? Like, they are the neighbor down the street that maybe you don't think too much about. But your channels are huge, like gigantic. Why do you, why do you think they hit with? people. I think it's that fear of the unknown and kind of everyone secretly acknowledging that the scariest things in the world are the things that we don't have any control over and that we don't know anything about. It's kind of that universal understood terror of what's lying beneath

the surface. Gio Rutherford is author of Spooky Lakes, 25 strange and mysterious lakes that dot our planet and creator of spooky lake content on TikTok and Instagram, you can find her at Geo Dosaurus. Geo, thanks for joining me. Thank you so much. I loved it. Before we wrap up this segment, we have a very special message. If you treat Halloween like a competitive sport, like many of us at Science Friday, we have a

challenge for you. We are holding a science-themed costume contest. And science-themed can mean a lot of things, from Frankenstein to the Fermi paradox. Go to ScienceFriday.com slash Halloween to enter you or your kids or your grandma's costume into the contest and get all the spooky details. You could win a swag bag. That's sciencefriiday.com slash Halloween. Okay, I'm going to dress up as a Gullam Yonka fish, I think. Perfect.

Wishing everyone a happy Halloween and many full-size candy bars. This podcast was produced by Charles Berkwist and Rasha Aireti. But a lot of folks help make this show happen every single week, including Annie Nero. Jason Rosenberg. John Dankoski. Danielle Johnson. I'm Flor Lickman. Have a great weekend.