WEBVTT - Why Is It So Hard to Get Rid of Lice?! 0:00:14.520 --> 0:00:17.880 You're listening to Part Time Genius, a production of Kaleidoscope 0:00:18.040 --> 0:00:19.040 and iHeartRadio. 0:00:23.360 --> 0:00:24.160 Guess what, Mango? 0:00:24.400 --> 0:00:25.160 What's that Mary? 0:00:25.600 --> 0:00:29.000 The oldest known sentence written in an alphabet is about lice. 0:00:30.000 --> 0:00:32.880 One. I don't know how that is possible, and to 0:00:33.320 --> 0:00:36.640 just saying the words lice is already making the itch. 0:00:37.120 --> 0:00:39.800 This is completely true. The sentence in question was written 0:00:39.840 --> 0:00:43.920 in Canaanite, which was the world's first letter based writing system. 0:00:43.920 --> 0:00:47.440 It began around five thousand years ago, and roughly translated, 0:00:47.560 --> 0:00:51.479 the sentence says, quote, may this tusk root out the 0:00:51.520 --> 0:00:56.360 lice of the hair and the beard. Archaeologists discovered these 0:00:56.440 --> 0:00:59.560 historic words inscribed on an ivory lyce comb that was 0:00:59.720 --> 0:01:03.320 estimated to be about three thousand, seven hundred years old. 0:01:03.680 --> 0:01:06.600 And if this com wasn't, you know, like a priceless artifact, 0:01:06.920 --> 0:01:10.119 you could still use it to delouse yourself. One side 0:01:10.160 --> 0:01:13.040 has wide teeth to detangle knots in your hair, and 0:01:13.080 --> 0:01:15.640 the other side has fine teeth designed to catch lice 0:01:15.680 --> 0:01:18.280 and knits, which of course are laus eggs. 0:01:18.720 --> 0:01:22.120 You know, I'm just imagining some parent almost four thousand 0:01:22.200 --> 0:01:24.520 years ago, grabbing this comb in a panic because their 0:01:24.600 --> 0:01:28.560 kid came home from school with lice, which honestly feels 0:01:28.720 --> 0:01:29.520 too relatable. 0:01:29.600 --> 0:01:32.120 Yeah, no, it really does well, and that's because like 0:01:32.120 --> 0:01:34.319 it or not, lice have always been with us, and 0:01:34.360 --> 0:01:37.480 today head lice are incredibly common. It is estimated that 0:01:37.520 --> 0:01:40.199 as many as one in four school children have them 0:01:40.360 --> 0:01:41.120 right now. 0:01:43.120 --> 0:01:45.600 And since it's back to school time right now in 0:01:45.680 --> 0:01:48.880 the Northeast, I've bet some of our listeners are dealing 0:01:48.960 --> 0:01:52.320 with this problem. So the good news is today on 0:01:52.360 --> 0:01:55.080 this show, we'll meet some scientists and some experts who've 0:01:55.080 --> 0:01:58.600 dedicated their lives to understanding these creepy crawleys and also 0:01:58.640 --> 0:02:00.960 finding ways to get them out of our hair. And 0:02:01.160 --> 0:02:04.720 of course we'll also discover some truly surprising facts about lice, 0:02:04.800 --> 0:02:07.840 including how they helped solve a long standing mystery about 0:02:07.920 --> 0:02:12.839 human evolution, and also why you can't ground them. And 0:02:13.120 --> 0:02:15.800 if you are someone in your household currently has lice, 0:02:15.960 --> 0:02:18.440 do not worry. We'll get into the science of what 0:02:18.480 --> 0:02:20.959 you should do and what you should do to deal 0:02:21.000 --> 0:02:46.360 with them. So let's dive in. Hey their podcast listeners, 0:02:46.360 --> 0:02:49.080 welcome to Part Time Genius. I'm Monga's Shatiicular and today 0:02:49.160 --> 0:02:52.880 I'm joined by my producer, Mary Super producer Mary, I 0:02:52.880 --> 0:02:55.840 should say, and over there on the other side of 0:02:55.840 --> 0:02:59.600 the soundproof glass drinking a big glass of whey and vinegar. 0:03:00.160 --> 0:03:02.360 It is our pal and producer, Dylan Fagan. 0:03:03.000 --> 0:03:05.160 I don't mean to yuck Dylan's yell. 0:03:05.120 --> 0:03:08.240 Oh you should, but yuck, that's so gross. 0:03:08.360 --> 0:03:08.760 I know. 0:03:08.919 --> 0:03:12.240 The concoction does not sound appealing at all, but according 0:03:12.280 --> 0:03:15.880 to a book of medical remedies written around sixteen hundred, 0:03:16.040 --> 0:03:19.280 it is a sure fire away to kill lice, and 0:03:19.800 --> 0:03:22.400 it's a lot simpler than another remedy that the same 0:03:22.440 --> 0:03:25.880 book suggests, taking powdered scrapings from the horn of a 0:03:25.919 --> 0:03:29.160 red deer, drinking some of it and sprinkling the rest 0:03:29.280 --> 0:03:32.480 on your head. I don't know. 0:03:32.520 --> 0:03:33.960 I feel like these things would just give you a 0:03:34.000 --> 0:03:36.200 stomach ache, although maybe that would distract you from being 0:03:36.240 --> 0:03:38.200 itchy at least, was that the idea. 0:03:38.520 --> 0:03:42.080 Maybe. What is interesting, though, is that even now in 0:03:42.120 --> 0:03:44.800 twenty twenty five, there are still a lot of weird, 0:03:45.000 --> 0:03:48.600 unproven home remedies floating around on the Internet. I found 0:03:48.680 --> 0:03:51.160 posts telling people to wrap their heads in duct tape 0:03:51.520 --> 0:03:54.400 or rub hot sauce on their hair, which I do 0:03:54.560 --> 0:03:57.120 not think is a good idea. There's also an old 0:03:57.160 --> 0:04:00.280 myth that kerosene kills lice, and that one's not just weird, 0:04:00.360 --> 0:04:03.680 it's also dangerous. There have been multiple cases of people 0:04:03.760 --> 0:04:07.440 suffering severe burns after applying kerosene and then getting too 0:04:07.520 --> 0:04:09.840 close to a pilot light or a cigarette. I mean, 0:04:09.840 --> 0:04:10.440 it's awful. 0:04:10.480 --> 0:04:13.640 Oh God, that is awful. Look, I understand the impulse 0:04:13.680 --> 0:04:16.080 because if you or your kids have lice, you will 0:04:16.120 --> 0:04:18.719 try anything to get rid of them. And I should 0:04:18.760 --> 0:04:22.400 know because I have had lice three times as an adult. 0:04:22.480 --> 0:04:25.320 I'll say it here for everyone listening. I managed to 0:04:25.360 --> 0:04:27.479 avoid it my entire childhood, but I have a school 0:04:27.520 --> 0:04:30.839 age child of my own now, and I guess we 0:04:30.880 --> 0:04:34.800 could say my luck ran out. Our first experience with 0:04:34.880 --> 0:04:38.320 lice was two years ago and it was completely miserable. 0:04:38.480 --> 0:04:41.200 Well, I can commiserate it, because you're definitely not alone. 0:04:41.279 --> 0:04:44.080 I also have school age children, and my families had 0:04:44.200 --> 0:04:47.719 lice so many times now. It is the worst and 0:04:47.839 --> 0:04:51.000 also something I just don't understand, because, like you, it's 0:04:51.000 --> 0:04:52.400 something I never got as a kid. 0:04:52.760 --> 0:04:54.919 Well, you know, as it happens. I know all about 0:04:54.920 --> 0:04:57.800 that because on the show, we do research. We talked 0:04:57.839 --> 0:04:59.800 to experts, that's what we do. So I took the 0:05:00.000 --> 0:05:03.080 already of calling up the real expert on your family's 0:05:03.240 --> 0:05:06.400 lice situation. I am referring to our friend of the show, 0:05:06.440 --> 0:05:09.040 occasional writer for the show, your wife, Lizzie. 0:05:11.360 --> 0:05:12.240 I don't like this at all. 0:05:14.680 --> 0:05:17.520 Tell me about the first time you guys had lace. 0:05:18.080 --> 0:05:19.920 What happened the first time is what has happened every 0:05:19.960 --> 0:05:24.039 single time since then, which is that all three of 0:05:24.120 --> 0:05:27.240 us get at ruby, Henry and me and Monkish does 0:05:27.480 --> 0:05:28.599 every single time. 0:05:28.839 --> 0:05:32.320 Do you resent Mangush for not getting lace one hundred percent? 0:05:32.600 --> 0:05:34.960 And he has like he'll do these theories about, oh, 0:05:35.040 --> 0:05:38.640 it's the kind of hair I have, And I'm like, no, 0:05:39.080 --> 0:05:43.320 because our children share, you know, some of your hair qualities. 0:05:43.360 --> 0:05:46.159 It's just that they they rub up all over me 0:05:46.400 --> 0:05:48.880 and they just do that to Mungash in the same way. 0:05:48.920 --> 0:05:50.480 So it's like, that's kind of all it is. 0:05:51.279 --> 0:05:53.960 Oh man, I just remember one of those times, I 0:05:54.000 --> 0:05:57.000 was like, Henry, were you close to anyone's head or 0:05:57.200 --> 0:06:00.240 do you know anyone who was itching? And he didn't 0:06:00.240 --> 0:06:02.080 think of anyone when I asked him, you know, he 0:06:02.160 --> 0:06:03.720 was like four or five at the time. And then 0:06:03.920 --> 0:06:06.479 later he was telling me about this game he knew 0:06:06.600 --> 0:06:09.560 friends played where and part of the game involved pressing 0:06:09.600 --> 0:06:12.320 your forehead against another kid's forehead to share thoughts and 0:06:12.360 --> 0:06:15.720 then run away. And it was so horrified. It was like, 0:06:16.000 --> 0:06:18.520 I asked you both these things specifically, and you were 0:06:18.560 --> 0:06:19.240 playing a game that. 0:06:19.400 --> 0:06:22.000 Basically you said ahead. You didn't say fourhead. 0:06:22.200 --> 0:06:24.960 That's true, but I mean he basically could have built 0:06:24.960 --> 0:06:27.200 a bridge from his head to his friend's head. It's 0:06:27.360 --> 0:06:30.640 just to like encourage the lights to walk over. But 0:06:31.480 --> 0:06:35.160 I remember a nurse examining our hair in our classrooms 0:06:35.160 --> 0:06:37.400 as a kid and telling us that certain hair was 0:06:37.400 --> 0:06:40.160 more resistant to lice. And I'm sure that's what I 0:06:40.160 --> 0:06:41.919 said to Lizzie at some point when she was just 0:06:42.480 --> 0:06:43.640 exasperated with me. 0:06:43.960 --> 0:06:47.560 Well, I mean, that would be nice, But scientifically speaking, 0:06:47.560 --> 0:06:49.320 there's not a lot of evidence for that. What we 0:06:49.360 --> 0:06:52.479 know is that anyone with hair can get lce, and 0:06:52.560 --> 0:06:55.640 direct physical contact head to head or forehead to forehead 0:06:55.680 --> 0:06:58.719 in your kid's case, is what makes it happen. Data 0:06:58.720 --> 0:07:02.240 from schools have found really or social patterns of life's transmission. 0:07:02.320 --> 0:07:05.279 So for example, a kid with lice might not spread 0:07:05.320 --> 0:07:07.040 it to the kid who sits right next to them 0:07:07.080 --> 0:07:09.880 in class, but they do spread it to their best 0:07:09.920 --> 0:07:12.040 friend who sits on the other side of the room, 0:07:12.640 --> 0:07:16.000 because at recess those kids are closer. Maybe they're hugging 0:07:16.120 --> 0:07:20.200 or leaning their heads together to talk or transmit ideas telepathically. 0:07:20.480 --> 0:07:24.520 Right, Yeah, that makes sense. But are you saying everyone's 0:07:24.600 --> 0:07:27.400 risk of getting lice is the same if head to 0:07:27.440 --> 0:07:28.520 head contact is equal. 0:07:29.280 --> 0:07:32.920 Not necessarily. It's possible lice may have a harder time 0:07:32.960 --> 0:07:36.000 gripping hair shafts that are naturally kinky or curly, and 0:07:36.320 --> 0:07:38.640 there have been some studies that have found lower rates 0:07:38.680 --> 0:07:43.640 of infestation among Black Americans compared to Americans of other ethnicities, 0:07:43.720 --> 0:07:47.160 but that could also be related to different grooming practices, 0:07:47.240 --> 0:07:50.000 different hair care products. On the flip side, there's some 0:07:50.080 --> 0:07:53.480 data and anecdotal report suggesting that there are people who 0:07:53.480 --> 0:07:57.720 are super spreaders of lice, that is, they have lice more. 0:07:58.480 --> 0:08:00.880 But whether that means they're more likely to get them 0:08:01.040 --> 0:08:03.040 or to have a harder time getting rid of them, 0:08:03.120 --> 0:08:06.120 we just don't know either way. The bottom line is, 0:08:06.160 --> 0:08:08.160 if you learn nothing else from this show, it is 0:08:08.200 --> 0:08:10.920 that no one is totally immune to lie. If you 0:08:10.960 --> 0:08:12.600 have hair, you can have lice. 0:08:13.000 --> 0:08:16.480 Got it, So no more bragging about my miraculous lice immunity. 0:08:17.720 --> 0:08:21.160 That's a mosquitoes love me so like, it's not all bugs, 0:08:21.160 --> 0:08:23.600 it's just lice that seemed to have woin me. But 0:08:24.040 --> 0:08:27.280 it's interesting that there are all these unanswered questions about 0:08:27.320 --> 0:08:29.520 who might be at greater risk for lice, Like, is 0:08:29.560 --> 0:08:31.600 that a big area of research right now? 0:08:31.680 --> 0:08:34.360 Well, there certainly are scientists who are really interested in 0:08:34.400 --> 0:08:36.600 this stuff, But the fact is, head lice are not 0:08:36.679 --> 0:08:40.679 a big priority for research funding. They're considered an annoyance, 0:08:40.760 --> 0:08:44.080 not a real medical problem, which I totally understand. But 0:08:44.720 --> 0:08:46.920 the first time you find a lous in your kid's hair, 0:08:47.000 --> 0:08:49.120 it sure feels like a real problem. 0:08:49.240 --> 0:08:49.800 Oh my god. 0:08:49.840 --> 0:08:52.360 I know. Before we go any further, I think we 0:08:52.360 --> 0:08:54.880 should clarify that for most of this episode we are 0:08:54.920 --> 0:08:58.760 talking about human head lice. There are actually three types 0:08:58.800 --> 0:09:02.640 of human lice, pubic lice or crab lice. Those are 0:09:02.679 --> 0:09:05.600 distantly related to head lice and body lice. They're kind 0:09:05.600 --> 0:09:08.800 of their own thing. And then body lice are very 0:09:08.800 --> 0:09:11.599 closely related to head lice, but they took a fascinating 0:09:11.640 --> 0:09:15.640 evolutionary detour that's made them different in a few critical ways. 0:09:15.920 --> 0:09:18.679 Body lice feed on our blood, just like head lice do. 0:09:19.280 --> 0:09:21.200 But they figured out how to live and lay their 0:09:21.200 --> 0:09:24.080 eggs in our clothing instead of our skin or our hair, 0:09:24.679 --> 0:09:27.760 and that actually helped solve a long standing mystery about 0:09:27.840 --> 0:09:31.720 human evolution, the question of when people began wearing clothes. 0:09:32.280 --> 0:09:34.480 I never thought about that question before, but now I 0:09:34.520 --> 0:09:35.640 want to know the answer. 0:09:36.720 --> 0:09:39.160 Well, for a long time, the best estimate we had 0:09:39.360 --> 0:09:42.240 was that it happened sometime between forty thousand and three 0:09:42.360 --> 0:09:45.160 million years ago, so there's a huge gap in there. 0:09:45.520 --> 0:09:47.000 That's not really a satisfying answer. 0:09:47.040 --> 0:09:49.920 It doesn't really answer the question. But the problem is 0:09:50.040 --> 0:09:54.080 early clothing was handmade from animal hide stuff that decayed easily, 0:09:54.160 --> 0:09:58.360 so there's really no record for modern scientists to study. Then, 0:09:58.520 --> 0:10:02.040 in twenty ten, came up with a much more specific 0:10:02.080 --> 0:10:04.679 time frame for the advent of clothing, and they did 0:10:04.679 --> 0:10:08.640 this by analyzing DNA sequences of body lice and head lice. 0:10:09.080 --> 0:10:11.560 They were able to determine that body lice emerged as 0:10:11.600 --> 0:10:14.920 a distinct ecotype of head lice at least eighty three 0:10:15.000 --> 0:10:18.160 thousand years ago, and possibly as early as one hundred 0:10:18.160 --> 0:10:21.079 and seventy thousand years ago, which means that's the period 0:10:21.120 --> 0:10:24.719 when humans began wearing clothing, because otherwise there would have 0:10:24.760 --> 0:10:27.920 been no evolutionary incentive for lice to change. And it 0:10:27.920 --> 0:10:29.880 turns out we have a lot more to learn from 0:10:29.960 --> 0:10:34.320 ancient lice. I can sum it up in a single word, archaeoparasitology. 0:10:34.600 --> 0:10:37.360 That feels like it should be multiple words. That's one word. 0:10:37.640 --> 0:10:43.120 I know it's too long to be three scrapple bingos, 0:10:43.800 --> 0:10:45.599 but it is exactly what it sounds like. It's the 0:10:45.640 --> 0:10:48.559 study of parasites in the context of archaeology, So that 0:10:48.600 --> 0:10:52.440 means looking at how parasites affected ancient people and even 0:10:52.480 --> 0:10:56.800 studying evidence of parasites in mummies. Now, thanks to this discipline, 0:10:56.800 --> 0:11:00.200 we know that lice were widespread in prehistoric times. The 0:11:00.240 --> 0:11:03.680 oldest direct record of lice infestation is a ten thousand 0:11:03.760 --> 0:11:07.080 year old intact louse egg that was found in a 0:11:07.120 --> 0:11:08.560 Brazilian mummy's hair. 0:11:08.960 --> 0:11:12.520 Wow, so that's thousands of years before the inscribed louse 0:11:12.559 --> 0:11:14.200 comb I told you about at the top, and even 0:11:14.240 --> 0:11:18.160 more thousands of years before Dylan's vinegar and waite concoction. 0:11:18.920 --> 0:11:20.920 So what did people do back then to get rid 0:11:20.960 --> 0:11:21.680 of lice? Do we know? 0:11:22.520 --> 0:11:25.120 Yeah? In prehistoric times, one of the most common ways 0:11:25.120 --> 0:11:27.720 of dealing with lice was to simply pick them out 0:11:27.760 --> 0:11:30.200 of people's hair and eat them. And we know that 0:11:30.280 --> 0:11:33.559 happened because adult lice have been found in copper lights, 0:11:33.559 --> 0:11:38.280 which is of course fossilized extrement, which is gross. Yeah, 0:11:38.320 --> 0:11:40.560 but it's also kind of wonderful, right, Like, the historic 0:11:40.600 --> 0:11:42.640 record is written in places where a lot of us 0:11:42.960 --> 0:11:45.720 would never really think to look. So I'm grateful for 0:11:45.760 --> 0:11:48.320 the people who dig through it, literally, and I'm also 0:11:48.360 --> 0:11:50.600 grateful that I don't have to eat my kid's lice. 0:11:50.800 --> 0:11:53.840 Yeah, we've come a long way. We've come a long way. Well, 0:11:53.880 --> 0:11:56.640 speaking of which, I want to fast forward from prehistoric 0:11:56.720 --> 0:12:00.920 to medieval times because during the Middle Ages, people developed 0:12:01.040 --> 0:12:04.599 some pretty wacky theories about where lice and other parasites 0:12:04.640 --> 0:12:08.839 come from. They didn't understand how transmission happened, so they 0:12:08.880 --> 0:12:13.600 concluded that lice were the result of spontaneous generation. In 0:12:13.640 --> 0:12:17.320 other words, they believed lice originated in so called corrupt 0:12:17.360 --> 0:12:20.599 matter like dirt and bodily fluids, which is how he 0:12:20.720 --> 0:12:22.760 got the idea that having lice is a sign of 0:12:22.800 --> 0:12:25.600 bad hygiene, an idea that's kind of still around today, 0:12:25.640 --> 0:12:28.120 even though we know it's really not true. But there 0:12:28.200 --> 0:12:30.839 was another way of looking at lice. Back then, some 0:12:30.880 --> 0:12:36.560 people viewed lice infestation as proof of humility and moral goodness, so. 0:12:36.760 --> 0:12:38.800 They actually thought that lice were a good thing. 0:12:39.240 --> 0:12:42.800 Yeah, because holy men and women often gave up grooming 0:12:42.840 --> 0:12:45.959 along with other worldly concerns, so if they got lice, 0:12:46.080 --> 0:12:48.640 instead of removing them, they would just ignore them, which 0:12:48.679 --> 0:12:51.920 of course meant they spread. There was actually this bishop 0:12:52.040 --> 0:12:55.839 named Thomas Decantelope, that was his name, who was canonized 0:12:55.840 --> 0:12:59.000 in thirteen twenty, and during that process some of his 0:12:59.080 --> 0:13:02.440 servants testify on his behalf that he was always covered 0:13:02.440 --> 0:13:04.440 in lice, and this was meant to prove that he 0:13:04.559 --> 0:13:07.120 was a true man of God who didn't allow himself 0:13:07.200 --> 0:13:10.640 to be distracted by frivolous things like combing his hair. 0:13:11.040 --> 0:13:13.680 That sounds absolutely miserable. 0:13:13.600 --> 0:13:16.480 That was the point. But just how miserable Bishop to 0:13:16.559 --> 0:13:20.560 Cantelope was would depend on his immune system, because the 0:13:20.720 --> 0:13:23.480 itching we experience when we have lice is an allergic 0:13:23.520 --> 0:13:26.800 reaction to the lous bites, and some people have milder 0:13:26.840 --> 0:13:29.800 reactions than others. In fact, some people don't really itch 0:13:29.840 --> 0:13:32.319 at all, which of course makes it easier for them 0:13:32.360 --> 0:13:35.240 to spread lice because they are not immediately aware that 0:13:35.280 --> 0:13:35.920 they have them. 0:13:36.600 --> 0:13:40.000 I mean, I think my son ished his head a lot, 0:13:40.120 --> 0:13:44.800 but Ruby didn't really, And I mean I remember thinking like, 0:13:44.880 --> 0:13:47.560 how can there be so many lice? Heer in not 0:13:47.600 --> 0:13:48.319 scratching harder. 0:13:48.960 --> 0:13:51.120 My kid was the same way. I was so itchy. 0:13:51.200 --> 0:13:53.880 I couldn't sleep when I had lice because I was 0:13:53.960 --> 0:13:57.120 itching so badly. Meanwhile, my kid is just walking around 0:13:57.120 --> 0:13:59.800 and he actually did have more lice than I did 0:14:00.280 --> 0:14:02.880 in the final tally. But I just must be more 0:14:02.920 --> 0:14:05.480 sensitive to the bites, you know, like some people get 0:14:05.559 --> 0:14:08.760 itchier with a mosquito bite than other people. It's just 0:14:08.800 --> 0:14:09.800 your immune system. 0:14:09.840 --> 0:14:13.000 Well, I was definitely scratching a lot, just knowing that 0:14:13.040 --> 0:14:15.960 my kids had lice and I didn't have any. But 0:14:16.000 --> 0:14:18.320 the good news is there are ways to deal with 0:14:18.400 --> 0:14:21.800 lice that don't involve vinegar, kerosene or becoming a saint. 0:14:22.000 --> 0:14:24.160 And after this quick break, we're going to hear from 0:14:24.200 --> 0:14:27.960 a scientist. He invented something called the lausbuster, and we'll 0:14:28.040 --> 0:14:32.040 learn how a common skincare product makes lice explode. So 0:14:32.560 --> 0:14:49.920 don't go anywhere. Welcome back to a very itchy episode 0:14:49.960 --> 0:14:52.400 of Part Time genius. I know this is a weird 0:14:52.440 --> 0:14:54.640 thing to say when we're talking about lice, but if 0:14:54.680 --> 0:14:57.520 you enjoy what you're hearing, please leave us a nice 0:14:57.600 --> 0:14:59.800 rating and review and share this episode with a friend. 0:15:00.000 --> 0:15:02.440 If you know anyone who's a parent of school age kids, 0:15:02.880 --> 0:15:06.320 I guarantee they'll want to hear this part at least. Okay, Mary, 0:15:06.360 --> 0:15:09.440 So here's something I learned about back when my kids 0:15:09.440 --> 0:15:12.160 first Got Life, and that is the fact that a 0:15:12.200 --> 0:15:14.480 lot of the over the counter a chemical products just 0:15:14.640 --> 0:15:18.120 don't work. In fact, my friend Nick, who grew up 0:15:18.880 --> 0:15:21.280 closer to my age, he said that he used to 0:15:21.320 --> 0:15:23.160 Get Life so much that his friends used to call 0:15:23.240 --> 0:15:25.200 him Nix because there was a product called Nicks. 0:15:25.400 --> 0:15:25.600 Yeah. 0:15:25.760 --> 0:15:29.240 Yeah, yeah, it's still on the lind Yeah. But I 0:15:29.320 --> 0:15:31.040 looked into it and it turns out that lies have 0:15:31.200 --> 0:15:35.000 developed resistance to the insecticides that were used for years 0:15:35.040 --> 0:15:38.920 to treat people like Nick. And this is just a 0:15:39.000 --> 0:15:41.240 natural thing that happens. And we see this with other 0:15:41.280 --> 0:15:44.400 bugs too. For example, farmers often have to come up 0:15:44.440 --> 0:15:48.480 with solutions when pests develop resistance to common ag pesticides. 0:15:49.120 --> 0:15:54.120 Another analogy, and one that's really serious, is antibiotic resistance, 0:15:54.200 --> 0:15:56.440 right you hear about this all the time, But these 0:15:56.480 --> 0:16:00.520 examples all follow the same evolutionary principle. Some bo are 0:16:00.600 --> 0:16:03.920 able to survive exposure to chemicals or drugs, and they 0:16:03.960 --> 0:16:08.080 pass that hardiness onto their offspring, and over time those 0:16:08.240 --> 0:16:11.480 traits just get stronger and stronger. The resistance spreads through 0:16:11.520 --> 0:16:13.800 the population and it's awful for us. 0:16:14.120 --> 0:16:16.040 Yeah, yeah, no, I've heard about this. In the case 0:16:16.040 --> 0:16:19.120 of antibiotic resistance, I know it can have really serious 0:16:19.200 --> 0:16:20.560 public health consequences. 0:16:21.240 --> 0:16:23.960 Yeah. So, Luckily, headlights are different in that they don't 0:16:23.960 --> 0:16:27.120 carry disease. So even if your drug store shampoo doesn't work, 0:16:27.400 --> 0:16:30.040 having headlights won't make you sick. It just really makes 0:16:30.080 --> 0:16:33.640 you itchy. Now, body lies are a different story. Remember 0:16:33.680 --> 0:16:35.840 we talked about how they evolve the ability to live 0:16:35.840 --> 0:16:38.960 in our clothes instead of our hair. Well, somewhere along 0:16:39.000 --> 0:16:42.560 the way they also managed to become disease vectors. So, 0:16:42.840 --> 0:16:47.120 during World War One, a disease called trench fever affected thousands, 0:16:47.200 --> 0:16:50.240 maybe even millions, of troops, and doctors discovered later that 0:16:50.280 --> 0:16:52.640 it was caused by a bacteria carried by the common 0:16:52.680 --> 0:16:56.320 body loss, which flourished in the crowded conditions of trench 0:16:56.360 --> 0:16:59.920 warfare now. Dale Clayton at the University of Utah is 0:17:00.000 --> 0:17:03.400 an evolutionary biologist and life expert, and he told us 0:17:03.400 --> 0:17:06.640 that this tiny but important difference is something he spends 0:17:06.680 --> 0:17:08.400 a lot of time thinking about. 0:17:08.920 --> 0:17:12.000 One of the most pressing questions about human life is 0:17:12.040 --> 0:17:17.280 why do we have life that vector nasty things, that 0:17:17.320 --> 0:17:21.600 live primarily in clothing but still take blood males from 0:17:22.000 --> 0:17:26.239 humans and life that are technically the same species that 0:17:26.320 --> 0:17:29.280 live on the heads of one out of four school 0:17:29.320 --> 0:17:32.840 kids all across the country, and one is dangerous and 0:17:32.880 --> 0:17:36.320 the other is basically harmless. And how long will it 0:17:36.400 --> 0:17:42.840 take before head life evolves the ability to vector nasty things? 0:17:42.840 --> 0:17:47.160 Will that ever happen? It could happen in ten years 0:17:47.520 --> 0:17:49.160 or a million years, We don't know. 0:17:50.080 --> 0:17:52.440 Okay, First of all, I realize it is the scientific 0:17:52.520 --> 0:17:55.480 term for what lifess do, but taking blood meals from 0:17:55.560 --> 0:18:00.399 humans sounds like the tigeline for a horror movie. I'm 0:18:00.520 --> 0:18:03.199 to have chills just thinking about this. But and second, 0:18:03.520 --> 0:18:06.240 this is actually terrifying. Is he saying that headlights could 0:18:06.240 --> 0:18:08.080 evolve the ability to make us sick? 0:18:08.520 --> 0:18:12.520 Yeah? I mean it is possible. There's no indication it's happening, right, now, 0:18:12.560 --> 0:18:15.399 but this is the kind of thing evolutionary biologists have 0:18:15.480 --> 0:18:18.200 to consider, which is why it's in our best interest 0:18:18.240 --> 0:18:21.600 to have a really effective way of treating headlince. But 0:18:21.800 --> 0:18:24.240 to back up for a second, Dale actually does most 0:18:24.280 --> 0:18:27.080 of his work with feather lice that live on birds. 0:18:27.760 --> 0:18:31.240 Unlike human headlights, they don't take blood meals. They eat feathers, 0:18:31.359 --> 0:18:33.880 which is pretty wild to think about, and he's been 0:18:33.880 --> 0:18:37.119 working with feather lice for decades. In fact, when he 0:18:37.200 --> 0:18:39.639 was a grad student, he named a new species of 0:18:39.720 --> 0:18:43.760 owl feather laughs, after the cartoonist Gary Larson, who was 0:18:43.920 --> 0:18:45.960 so excited that he drew a picture of it and 0:18:46.040 --> 0:18:49.240 published it in his nineteen eighty nine book The Prehistory 0:18:49.280 --> 0:18:50.200 of the Far Side. 0:18:50.280 --> 0:18:52.639 I wasn't sure where that was going, but that is 0:18:52.680 --> 0:18:54.560 not where I thought we would end up. I do 0:18:54.640 --> 0:18:56.879 love it, though. What a strange honor to have a 0:18:56.960 --> 0:18:57.879 laus named after you. 0:18:57.880 --> 0:18:59.679 It's kind of wonderful, it really is. 0:18:59.760 --> 0:18:59.800 So. 0:19:00.200 --> 0:19:03.360 As a veteran life expert, of course, Dale knew about 0:19:03.440 --> 0:19:07.520 human headlights developing resistance to insecticides, but he wasn't focused 0:19:07.560 --> 0:19:10.240 on finding a treatment for them until his own kids 0:19:10.280 --> 0:19:12.800 got lice and he realized he didn't know what to do. 0:19:13.920 --> 0:19:16.880 My wife was kind of angry because she says, you're 0:19:16.920 --> 0:19:18.840 all the world authorities on lice and you don't even 0:19:18.840 --> 0:19:20.439 know how to get rid of lice on our kids. 0:19:20.520 --> 0:19:22.760 What's going on? So that was a motivator. 0:19:23.920 --> 0:19:26.320 I should note here that he's referring to his first wife. 0:19:26.400 --> 0:19:30.000 This is actually relevant to this discussion because his second 0:19:30.000 --> 0:19:34.040 wife also studies lie. They've even named species of lice 0:19:34.119 --> 0:19:35.080 after their kids. 0:19:36.200 --> 0:19:40.400 The dinner table conversations at the Clayton household must be fascinating. 0:19:40.680 --> 0:19:44.160 I think they probably are. Anyway, Dale's pondering his kids 0:19:44.240 --> 0:19:46.600 head lice, and then he remembers a weird problem he 0:19:46.640 --> 0:19:48.920 had back when he first moved to Utah. And this 0:19:49.000 --> 0:19:50.920 was after teaching in the Midwest and the UK. 0:19:51.640 --> 0:19:55.480 I discovered, to my dismay, I couldn't keep lice alive 0:19:55.520 --> 0:19:58.600 on pigeons here, and it took about a year to 0:19:58.600 --> 0:20:01.000 figure out that the reason is it's too arid. 0:20:02.320 --> 0:20:04.760 So what's interesting is that lice can't live in tanks 0:20:04.840 --> 0:20:07.879 or petri dishes. They can only survive on a living host. 0:20:07.920 --> 0:20:10.919 So when Dale was setting up his lab at the 0:20:11.040 --> 0:20:13.479 University of Utah, he got a bunch of pigeons so 0:20:13.520 --> 0:20:16.639 you could study their feather lice. And the pigeons were fine. 0:20:16.720 --> 0:20:20.400 The feather lice were not. Since they aren't blood sucking lice. 0:20:20.520 --> 0:20:23.520 They rely on moisture from the air for hydration, and 0:20:23.640 --> 0:20:26.280 the air in Utah is really dry, so the only 0:20:26.280 --> 0:20:29.240 way to keep his lab lice alive was to modify 0:20:29.320 --> 0:20:32.760 the ambient humidity. So when drug store shampoos failed his 0:20:32.800 --> 0:20:35.480 own kids, it occurred to him that maybe dry air 0:20:35.560 --> 0:20:38.200 could be the key to killing headlights that are resistant 0:20:38.240 --> 0:20:39.880 to all the chemical treatment. 0:20:40.520 --> 0:20:44.440 And so we started tankeering with different approaches. The University 0:20:44.520 --> 0:20:47.480 of Utah is one of the best universities in the 0:20:47.560 --> 0:20:53.800 country for entrepreneurial work. There's money for researchers to try 0:20:54.000 --> 0:20:59.000 weird things, get like pre med students involved in those projects, 0:20:59.080 --> 0:21:03.160 and so we started pursuing this possibility of using heated air, 0:21:03.960 --> 0:21:06.440 and after a while we figured out how to make 0:21:06.480 --> 0:21:09.800 it work, and then we got bigger dings to develop 0:21:09.880 --> 0:21:11.320 an actual medical device. 0:21:12.640 --> 0:21:16.359 Dale and his team called their invention the Lousebuster. The 0:21:16.480 --> 0:21:20.320