SciShow Tangents - Bats

Starting point is 00:00:00 Hello, welcome to SciShow Tangents, the likely competitive knowledge showcase starring some of those geniuses that make the YouTube series SciShow happen. This week joining me as always are Stephan Chin. Hello there. It's been a while since we recorded, so I actually haven't seen you in a while. How have things been going? Nothing's new. I'm still moving in. Oh, wow.

Starting point is 00:00:35 Very slowly. I take one thing out of the box each day. We're also joined by Sam Schultz. Hello. Who's got very blue hands right now. That was going to be my tagline. No, I don't have one. Oh, I didn't ask got very blue hands right now. That was going to be my tagline. No, I don't have one. Oh, I didn't ask Stefan what his tagline was.

Starting point is 00:00:49 Oh, channeling that big Zamboni energy. Ooh, I don't like it. Sam, sorry. Let's start all over again. Hi, Sam. Hi, Hank. So, tell me about your tagline then. Very natural intro. Oh, we're going to leave the firstline then. Very natural intro.

Starting point is 00:01:06 We're going to leave the first one in. Oh, okay. My tagline is currently covered in blue paint for a secret reason. We've also got Sari Riley. Hello. Hello. I'm waiting for a prompt, a question to answer. Sari, what is your tagline?

Starting point is 00:01:25 Yikes. Just several yikes or just one? Oh, just one yike. And I'm Hank Green. My tagline is all new skin. Our worst intro yet. I think it was tight. Tight as a mofo right there.

Starting point is 00:01:43 That was really together. Every week here on SciShow Tangents, we get together to try to one-up, amaze, and delight each other with science facts. We're playing for glory and also playing for Hank Bucks. I've had several people reach out on Twitter and they say to me, you know, you should probably keep track of who's doing good in the Hank Bucks department. So maybe we should do this. Early on, there was a good reason not to. Yeah. Because we weren't doing them in order. Oh, now we are. Now we can. I think we'll probably be totally fine. Okay, let should do this. Early on, there was a good reason not to. Yeah. Because we weren't doing them in order.

Starting point is 00:02:05 Oh, now we are. Now we can. I think we'll probably be totally fine. Okay, let's do it. We can figure out a way to do that. Okay. Yeah, I want people to be into the metagame of all of this. Mostly I'm scared that it'll be very skewed in some way and we won't realize it.

Starting point is 00:02:19 Skewed towards me. Probably skewed towards Sam. Since the show is called SciShow Tangents, you might expect that we go off on some of those, but we try to stay on topic, and if we go off on a tangent, if it is deemed to be unworthy, the rest of the team can force you to give up a hank buck for your bad tangent. Now,

Starting point is 00:02:36 as always, we introduce this week's topic with a traditional science poem this week from Sari Reilly. There are plants shaped like pitchers with fluid within, and digestive enzymes to break down what has been unlucky enough to fall into these traps, except for one species. It's perfect for naps. Its mammalian tenants get sleepy by day, need a safe haven to roost and keep predators away. Whether they're flying solo or a mom-baby pair, cute woolly bats snuggle in and take care. Now you might ask, what's the

Starting point is 00:03:06 plant get from it? Well, the bats pay their dues, and their currency is shit. Nitrogen-rich bat guano is a precious treat for a plant starved by poor soil that just wants to eat. So a bat and its toilet, what a friendship, what a team. And bat poop, I guess, is worth more than it seems. Ah, this week's topic is bats, not poop, not pitcher plants. I know. There could be a lot of different things. Oh, mutualistic relationships. Not mutualistic relationships, but just generally bats.

Starting point is 00:03:37 That's a good bat fact that you turned into a very good column. Very good. Usually, Sari defines our topic for us. Do you have a what is a bat? What is a bat? What is a bat? Are they all related to each other or did they ever convergently evolve? I don't actually know the answer to that question.

Starting point is 00:03:52 They're all related to each other as far as I know. Yeah, I think that is the case. They're in an order called chiroptera. Do you know what their clade is? I don't. Because I know what their clade is. What's a clade? A clade is a taxonomical

Starting point is 00:04:05 subcategory, basically. I think it's a category within another taxonomical category, but there's lots of different kinds of clades. But they are in the clade scrotifera, which is mammals with scrotums. Though we are not in scrotifera, which is a little confusing. Why not? Is ours different? Ours is different. I think that our scrotums evolved separately from bat scrotums. But I'm not sure. I just know that we're not in scrotifera and bats are. So all scrotifera evolved from one ancient scrotum.

Starting point is 00:04:36 Correct. Yeah, I mean, they definitely came from the genes contained in one ancient scrotum. Yes. That's beautiful. There's something poetic about it. But sorry I interrupted because I wanted to talk about scrotums. Does anybody want to charge me for that? I don't think so.

Starting point is 00:04:52 I liked it. Yeah, bats have scrotums, part of the definition of a bat. They also have, they're the only mammal that actually flies. So there are other mammals that can glide. They have membranes between their limbs, but bats have modified arms, essentially, that they can flap and fly through the air and don't just soar down like a flying squirrel or a colugo or something like that. And all bats have a common bat ancestor. As far as I know, yes. Papa Scroat, I think they called him. I know, yes.

Starting point is 00:05:22 Papa Scroat, I think they called him. And they're the second largest order of mammals, which I thought was interesting, like by number of species that they have. Wait, second largest? Yeah. I thought they were the largest. Yeah, I thought so too. Rodents, yeah. Oh, rodentia. You're learning from the show.

Starting point is 00:05:42 And some of them eat insects or fruit. Those are the two main categories of bat food. And blood. What about the drinking blood? Yeah, then there are vampire bats who are off in their own corner. And they gave all other bats a really bad name, basically, right? I think also bats carry a lot of diseases, and especially viruses and stuff that are transmissible to humans

Starting point is 00:06:05 which probably helped spread the vampire myth okay so we know what bats are yes they're cute too i think they're really cute yes they're cute i already did they're fuzzy cute fly balls are even the big ones cute like the two to three meter wingspans? Like a flying fox? Yeah. I would be free to go flying fox. And now it is time for Truth or Fail. One of our panelists has prepared three science facts for our education that enjoy...

Starting point is 00:06:36 One science fact. Hopefully you've listened to previous episodes and know how this segment works already. So there's two fake facts, one true fact. And the other panelists have to figure out either by luck or wild guess which is the true fact. If we do, we get a Hank Buck. If we don't, then Stefan gets that Hank Buck. Give me it.

Starting point is 00:06:55 Stefan, what are your bat facts? Fact number one. The lesser short-tailed bat is the only species of bat that we know of that has evolved flightlessness. It lives in New Zealand and crawls around on all fours foraging for food and chews into trees to create little burrows for itself. Flightless bat! If that's not real, I'm gonna give you a hank fuck anyway. I'll take it. Fact number two. While the vast majority of bats are nocturnal, the Simone flying fox is the only bat that exhibits, quote, strong diurnal proclivities, meaning that they are active and forage during the daytime. Okay.

Starting point is 00:07:29 And number three. Weird. While most bats grab onto things with their feet and roost upside down, the bats in the genus Thyroptera are one of two bat genera that roost head up, but it's the only one that uses suction from little cups on its hands and feet to hang onto leaves so it can do that. That's cute. So we've got flightless bats that burrow into trees,

Starting point is 00:07:50 the daytime bat, and suction bat that roosts head up. Oh, man. There are so many different kinds of bats. So like any of these seem totally plausible. I am a big fan of the flightless bat, though, because I would never have thought of a flightless bat existing. But I it totally could it makes sense would you say it was from new zealand or something where there's also lots of flightless birds down there the diurnal bat seems the fakest to me because it feels like there'd be lots of diurnal bats yeah because like not all bats

Starting point is 00:08:20 are nocturnal i think which like by definition means that some of them have to be diurnal. Also, not all bats eat insects. So like there are bats that eat fruit and you don't need to look for fruit at night necessarily. Right. So are bats mostly nocturnal because that's when the bugs are out? I don't know. Why? Because it's not like they need to worry about predators too much, except for like, I guess, birds of prey, because it's going to be hard to catch a bat. Except for, like, I guess birds of prey. Because it's going to be hard to catch a bat. I am going to go for the lesser short-tailed bat.

Starting point is 00:08:51 The bat that does not fly. Flightless bat. I'm going to do suction cup bat also because I love it. I pick suction cup bat too. Okay. It was the suction cup bat. So the Simone flying fox is mostly diurnal. And there are a few species that we know of that fly around during the day.

Starting point is 00:09:11 But there's only like four species total. And they all live on islands where there are not predatory birds. I think the leading hypothesis for why bats became nocturnal in the first place is that when they were first evolving, they had to compete with predatory like hawks and owls and things. Who are probably way, way, way better at flying than they are. Yeah. Right.

Starting point is 00:09:31 Okay. And I typed in flightless bat into Google and I got the New Zealand lesser short-tailed bat. But it's not flightless. It's not flightless. It just crawls around a lot. Yes. It's just lazy.

Starting point is 00:09:40 around a lot. Yes. It's just lazy. No, I don't know why it does it, but that and the common vampire bat both spend a lot of their time on all fours. Walking around? Walking around. Lazy makes sense to me for that because it probably takes a lot of energy to fly. Yeah, but you go much faster than when you're just walking around with your big wings.

Starting point is 00:10:01 And it's like harder to run around when you have wing arms. Yeah, like your hands are just giant flaps of skin. Yeah, just like one knuckle, right? Because their wings are their digits spread out. But yeah, so those bats still fly. The New Zealand one does actually chew into trees to make little burrows for itself, whereas most bats roost. And these ones actually roost most of the time, just sometimes they chew

Starting point is 00:10:30 into a tree. So then the true thing was about the suction cups. And there are two genuses, Thyroptera, which are the disc-winged bats, but they use suction to stick onto leaves. And the other genus, Myzopoda, are called sucker-footed bats, but they don't use suction. They secrete a sticky, wet fluid from their pads. They just have stuff that leaks out of their fingers. I'm glad that's not me.

Starting point is 00:10:57 Well, you could climb stuff, though. But touching things, typing would be hard. Just wear gloves. And then you take your glove off at the end of the day and be like, look at all my goop that has been accumulating inside of my glove. You know, when you go to the bathroom, you change your glove. Right.

Starting point is 00:11:14 I like this. I like this speculative universe in which everybody has to change gloves every 30 minutes. Because we evolved from sticky people. All right. Next up is the fact off. But first, a word from our sponsors. Now get ready for the Fact Off. Two panelists bring science facts.

Starting point is 00:11:53 That was a big one. Bring science facts to present to the others in an attempt to blow their minds. The presentees each have a hank buck to award the fact they like the most. So you award it to the one who blew your mind the most. It's gonna be me, because it's me versus Sam. I'm not saying that Sam... What? Whoa. I'm just saying it's gonna be me. I heard what you said.

Starting point is 00:12:15 You don't have the Dracula voice either to make it funny. It's me against Sam. I wouldn't stand a chance against Dracula. It's me against Sam, and I'm sure that we have equal chances of winning. The person who's going to go first is the one who most recently gave blood. When was the last time? It's been a long time.

Starting point is 00:12:33 It's been a long time. It's been a long time for me, too. I give blood to my doctor like once every. In fact, I'm scheduled to do it today. And I didn't. But I should have. Regularly. But this is to the people who

Starting point is 00:12:45 need it the vampires yeah i think i was in high school maybe okay a long time oh all right well it was definitely me then i got the good blood i got the universal donor blood so i feel bad not doing it yeah it makes sense um so i i probably gave blood the last like two three years ago i have b positive which is a nice little reminder for me i do too and my dad would always make jokes about it because i'm like not a super optimistic person all the time you just be like be positive siri just very weird go to go to yeah your room dad yeah i'm being an angsty teen right now i don't need that all right so i guess that means I go first Everybody you know about dolphins, right? Uh-huh. Yep. They are like bats in one way, but almost no other ways

Starting point is 00:13:31 We talked a little bit about how bats are in scrotifera But it turns out dolphins are also weirdly enough in scrotifera They don't have scrotums But they their ancestors do. They used to have a scrotum. They look so funny. Were they external? Yeah.

Starting point is 00:13:50 Yeah. Well, their ancestors were like cows and stuff. Like horses. Did they just get bitten off one generation? No. It wasn't good for swimming. We need to do an episode about evolution. We did one.

Starting point is 00:14:05 I know. Yeah, we do. I know. Yeah, camels, pigs, ruminants, and whales are all sort of like together. Cool. And so those things have scrotums, but the dolphins,

Starting point is 00:14:15 that would be really uncomfortable if they're just hanging out flopping in the... Yeah. Anyway, that's not what my fact is about. It's not real. So they are

Starting point is 00:14:24 somewhat closely related. Like they're more closely related to each other than they are to us, for example. But they are very different things. Like it's a tiny fuzzy thing that flies in the air versus a big, not fuzzy thing that swims in the oceans and mostly just the oceans. But they do have this thing in common where they both echolocate. They see with sounds and they do it very efficiently and effectively. And this is a thing that evolved

Starting point is 00:14:49 and it evolved from two animals that like evolved independently of each other. But since they're fairly closely related animals, it turns out they evolved this in exactly the same biochemical way. So usually convergent evolution is a thing that happens when like, you know, a bat and a bird both have wings, but they got their wings in totally separate ways. Like a bird's wing is the whole arm. A bat's wing is just the fingers, is just a separate thing. But in this case, the same protein, Preston, in the ear, has the same mutations in it that makes it different from our Preston in dolphins as it does in bats.

Starting point is 00:15:31 They have the same different genes, but they evolved those different genes entirely separately. It's one of the best cases of convergent molecular evolution there is, and it was only recently discovered, and I find it very cool. That is very cool. What does the gene specifically do? Does it just like— It codes for like a little hair in your ear that hears better. Basically, it's a change that lets them hear more sensitively. That's interesting to me because dolphins also don't have big ears

Starting point is 00:16:05 to channel the sound in. Right, yeah. So the fact that they have the same mutation and that functions underwater and above water and without ear flaps. In like the ear area. Well, I assume dolphins have ears, but do they open to the outside world?

Starting point is 00:16:22 Because I know like there's whales that have like internal ears. I think it's whales. But then sound is transmitted through their jaw. There's like a material in their jaw that can transmit the sound to their ear canal. Dolphins do have a tiny tiny little ear hole.

Starting point is 00:16:37 Okay. It is pretty much invisible unless you're looking for it. But that is where the sound goes back in. Yeah. And that's where their little, their Preston hairs are. There are 14 points of mutation that they share with bats. And they all changed in exactly the same way. Whenever my son walks into a place that echoes,

Starting point is 00:16:57 like it's like, it sounds different because it's, you know, got some reverb quality. He goes, bop, bop, bop,

Starting point is 00:17:05 bop. And I'm like, you bop, bop, bop. And I'm like, you are echolocating, aren't you? Maybe he's got the little ears. It's super cute. Like, you walk into a tunnel and he's like, bop, bop. He's going to catch some bugs. So that's my fact.

Starting point is 00:17:21 Hit me, Sam. All right. So, bats echolocate to find food yeah i think all right bugs and one thing that they eat moths and this is a conjecture on my part but the moth seems like a pretty good food for a bat because they're big and they don't seem like they fly so great yeah and they're very easily confused by lots of stuff including light so they can just swoop around and eat them but there are some types of moths who have learned to fight back against bats. So there's a family of moths

Starting point is 00:17:47 called the tiger moth family, and they make clicking sounds by vibrating membranes inside of them. Scientists have known about this for a long time and that a lot of tiger moths are poisonous, and so they click to alert bats not to eat them because they are poisonous. But there's a type of tiger moth called the Bertholdia trigona,

Starting point is 00:18:08 which has way louder clicks and isn't poisonous. And nobody could figure out why until 2009. So in 2009, they tied a bunch of moths to the ceiling with like fishing line and they were just dangling down. And they let bats out into this room to eat the moths. And some of the moths could make the sound, and some of them had been altered so that they could not click. I'm sure in a very humane way.

Starting point is 00:18:31 Yeah, probably not just with a big needle poked through. So what they found was that the bats caught the non-clicking moths 400% more often than they caught the clicking moths. And the ones trying to catch clicking moths and the ones trying to catch clicking moths the bats trying to catch clicking moths looked confused and hesitant to try to catch the moth so what they determined after taking a closer look was that the moths could make 4500 clicks per second which basically made like a curtain of sound that the bats got like garbled feedback from their echolocation jammed the radar yeah totally so they couldn't tell where the moth was so they would like swoop in bit into like thin air and not be

Starting point is 00:19:10 Able to grab the moth. That's it I also we did a side show on Various moth strategies for not getting eaten by bats and it's also potentially why they're fuzzy because it like the echolocation bounces back less less sound foam yeah it's sound foam for for moths well some moths have just devoted their lives to not getting eaten by bats which is probably a pretty good strategy for a slow moving, juicy bit of food that lives in the air. How do they make the clicks?

Starting point is 00:19:49 Do you know anything about the organ that does that? I couldn't find anything that described it super. It just said membranes inside of them. Clicky membrane. And so the poisonous ones make a lot softer clicks that the bats avoid.

Starting point is 00:20:05 Right. The louder ones, the bats don't avoid. So that's why they were like, what's going on here? I mean, my thought would be like, they're just trying to pretend. Like, I'm also clicky. Yeah. I'm poisonous like a mimic. And there are non-poisonous ones that do that too.

Starting point is 00:20:20 Okay. These ones just like, they're so loud you can hear them without any kind of like special equipment you can just hear them flying around in fields all right those were two very good facts i have no idea what i would choose but me though i'm gonna give mine to sam because that was more mind-blowing to me just like learning about the curtain the sound really good it is they're jamming the radar of a convergent molecular evolution i know 14 points do have a good probability well mine's that probability too right sam's is less mind-blowing from a statistical standpoint but the mechanism is more mind-blowing so Memories. So I'm going to give it to Sam. No!

Starting point is 00:21:07 I was very satisfyingly mind-blown by both. Okay. Yes. But I got more points. You're banished. I will survive. It is now time to ask the science couch

Starting point is 00:21:18 where we ask listener questions to our couch of finely honed scientific minds. At Gannon188 and at BiologyAlex ask, is there any cure for the fungus, aka white nose syndrome,

Starting point is 00:21:29 that's wiping out the United States Northeast population of bat? You're looking at me like I have any idea. I have never. I got nothing. Have you heard of white nose syndrome before? Yeah, it's definitely a problem. And the question has been, in my understanding, is this just a really bad pathogen or is there some human cause that is making it worse like pesticides or habitat loss or something that is making it more common for it to be spread more easily?

Starting point is 00:21:57 And I don't know the answer to that. I saw a picture and it looks a lot like moldy nose. Yeah. It's like you get a fungus face. Is fungus and mold, are those the same thing? Yeah. Mold is a fungus. So, yeah, it is a lot like moldy nose. Yeah. It's like you get a fungus face. Is fungus and mold, are those the same thing? Yeah. Mold is a fungus. So yeah, it is a fungus.

Starting point is 00:22:09 I don't know if we're confused about how or why it spreads. But it started in winter 2006 in Albany, New York. As far as we know, it was probably other places too. But that was the first documented case of it where they found dead bats with white fuzz around their nose. It's a fungus called, oh gosh, I couldn't find a pronunciation, so this is just me doing my best with my biology knowledge. Pseudogymnoascus destructans. That's a bad name. Yeah. I don't want that. This one bad. And it attacks the skin of bats. So that's why it shows up around their nose because that's not where there is fuzzy but it also attacks like their wing tissue anywhere that is exposed skin

Starting point is 00:22:52 and essentially what it does is like this attack on their immune system makes them wake up when they should be hibernating so during the winter times during the day times, during the day times, and use their fat reserves when they should be conserving energy. So it destroys their tissue and then leads to really malnourished looking bats. Really, their wings tighten up for some reason. Weird. I think it's like whatever makes it flexible maybe gets destroyed. I watched a video and a woman was pulling on a bat wing, which would normally stay extended and it like contracted really quickly. Why does it wake them up? Because they're in pain or something or just messes them up?

Starting point is 00:23:32 I think so. I think it like messes up something with their internal systems. I don't know exactly how it attacks them, but it's like a bad infection. It'd be like getting a bad cold, but fungus in your body, I guess, which is not the same as a cold. One source that I was reading called it one of the worst wildlife diseases in North America. So since winter 2006, it's killed over 6.7 million bats by some estimates, which is a lot. And it can kill 70 to 90% of bats in an infected, I love this word, hibernaculum, which is the place where bats gather to all hibernate in a group.

Starting point is 00:24:11 Oh, yeah, nice. So it's a hibernaculum of bats. Do they hibernaculate? Caves, probably. Yeah. General bat places. Okay, they don't have a special place. A lot of caves.

Starting point is 00:24:26 Yeah. And this is you can see maps of where this is found. It's mostly in the northeast U.S., mostly in Canada, like that general region. And they're finding it more and more western in the United States. And we've actually found this fungus infecting bats in other countries, like several other European countries and I think in China. But in the U.S., it's extremely deadly for some reason and we think it was transported over here by humans not by bats um because there's no way for a bat to migrate across the ocean in that way so it was probably like a human in a cave got the fungus on them spread it to a different cave and just like the colonizers,

Starting point is 00:25:06 we have infected the bat population right now, decimating them. So that is white-nose syndrome. We're trying to figure out possible cures for it. And a lot of the research that I found is pretty, like the beginning stages of it and pretty recent. So one main avenue is like people studying the DNA one main avenue is like people studying the dna of this fungus and they found that one it needs cold to grow like something about its genetic makeup makes it require cold so we should heat the earth up oh perfect we warm the planet global how would we do that uh good idea but i need some avenues at least the bats are going to be. So they're not entirely sure what to do with that information. But also during the same genetic research where they discovered that it needs cold to grow,

Starting point is 00:25:54 they also found that it's missing the repair mechanisms for DNA when it's damaged by UV light. So, I don't know, in all of our bodies, we have a bunch of cellular molecular biology mechanisms that, like, our DNA is constantly being damaged by UV light, having mutations, and then it goes back and fixes it. And so this fungus doesn't have it. So we need to shine the light on the bats. Yeah, they're trying to figure out a way. I think they called it a UV tunnel or something,

Starting point is 00:26:23 like constructing those at the entrance to caves have to like crawl through the uv light yeah or like they fly through it and get blasted by uv light which doesn't harm the bats because they have the repair mechanism but the fungus doesn't oh but it sounds extremely elaborate like you need a lot of yeah timing that would be good for maybe one cave at a time. They also found that there is a fungal compound that inhibits the growth of P. destructans. They had, I'm guessing, like dishes of P. destructans and then like sprayed this vapor, this mushroom vapor on them. Vaping that truffle butter. So we either, so okay, so our solutions are global warming, just UV tunnels, and the bats have to vape.

Starting point is 00:27:15 That sounds great for the bats. Yeah, they can like tan and vape. That's pretty cool. And one professor has tested bat vapes, but he called it a bat fogger instead. I think he used some sort of antifungal volatile organic compound, which is what this mushroom alcohol falls into. So some sort of chemical. I'm not sure if it was this exact one and sprayed a bunch of fog into an abandoned railway tunnel where bats roost. And the just the numbers were higher than they expected like this was a colony that they'd known was infected with white nose syndrome

Starting point is 00:27:50 it had been decimated in years past and it was like slightly higher than they expected it to be so maybe it helped we're not sure but it doesn't seem to be something that's going away on its own like i haven't heard as much about white nose syndrome as I did like in 2011, I feel like. But that's just because we got tired of talking about it, not because the problem's gone away. So the people who are studying these bats and studying white nose syndrome have also just been tracking numbers of like population numbers to see what is happening and where they have to concentrate their efforts. And it seems like certain colonies are rebounding by themselves. So like to give you a sense of the scale, one that they were monitoring had about 90 adult

Starting point is 00:28:32 bats in 2010. And then in 2018, when the article I'm reading is published, it rebounded to 200. And they're not entirely sure why, like is some sort of natural selection happening where maybe bats that are more resistant to the fungus and this disease are surviving and passing on the genes that help them? Or is it behavioral avoidance of sick bats? Like, are they learning some sort of behavioral trait? Are they, I don't know, is the fungus? Just going to lay out in the sun. Yeah.

Starting point is 00:29:00 Daytime just being like. What if we just like put a UV light in the cave and and be like if you guys want to use this you can just imagine leaving little presents in each of the bat cave it's like a little uv lamp a little vape pen here you go space heater yeah do with it what you will yeah um so yeah so so it is like a very intense very devastating thing and people are worried about the bats and it like sucks that it was probably human caused right and so humans want to try and fix it but epidemics happen in nature all the time and species adapt or bounce back or don't go extinct so something's gonna happen going to happen. Oh, no. I'll go shine lights on bats.

Starting point is 00:29:47 I'll do it. Sam's got a new job. He quits. Going to go to every cave. Yeah. If you want to ask the Science Couch, you can do that by following us on Twitter, at SciShow Tangents,

Starting point is 00:29:56 where we will tweet out the topics for each episode every week. All right. So it looks as if I lost. Sarah, you've got two points. Thank you. Oh, that's not a winning? Oh, no. No, it's not.

Starting point is 00:30:09 Stefan, you've got one point. Sam. Yeah? Pulling out the win with three Hank Bucks. How? I should have thought about the score.

Starting point is 00:30:17 Oh, I know how. Yeah. Oh, I did. One plus two. Sam, I don't trust you to tally up all our scores now. You better build a spreadsheet so I can check your math. All right. If you like this show and you want to help us out, it is super easy to do that.

Starting point is 00:30:34 You can leave us a review wherever you listen. That's going to help us know what you like about the show. And also other people will know that too. Second, you can tweet out your favorite moment from this episode. I love it when I see those. And finally, if you want to show your love for SciShow Tangents, tell people about us. Thank you for joining us today. I have been Hank Green.

Starting point is 00:30:53 I've been Sarah Riley. I've been Stefan Schitt. And I've been Sam Schultz. SciShow Tangents is a co-production of Complexly and WNYC Studios. It's produced by all of us and Caitlin Hoffmeister. Our art is by Hiroko Matsushima. And our sound design is by Joseph Tuna Medish. Our social media organizer

Starting point is 00:31:07 is Victoria Bongiorno and we couldn't make any of this stuff happen without our patrons on Patreon. Thank you! And remember, the mind is not a vessel

Starting point is 00:31:14 to be filled, but a fire to be lighted. But one more thing. Is it about bat poop? It is about bat poop. All my facts are about bat poop. They got good poop. They got great poop. Bat guano has a really high nitrogen content,

Starting point is 00:31:47 specifically compounds called nitrates, which if you put them through a couple synthesis process can be turned into things like fertilizer, but also gunpowder. And so at times like this particular one is a civil war. When supply chains were cut off to the Confederacy, they would go to bat caves, mine a bunch of bat poop, put them in kilns, and create gunpowder from poop.

Starting point is 00:32:11 So we killed each other with bat poop. Yeah. Leave it to humans. Yeah, it's the ingenuity of us. Bloodthirsty human being.

SciShow Tangents - Bats

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