ROBERT SIEGEL, HOST:
Our next story is about lice, and one biologist's mission to rid his home of them. Our tale begins with lice doing what they were born to do - infest. Here's NPR's Steve Henn.
STEVE HENN, BYLINE: When your kids are infested with head lice, a certain amount of panic, even desperation, can spread through a house. These bugs are basically harmless, but Sheri Nacht still knows too well the knot that can form in the pit of a parent's stomach at the sight of a louse. Sheri's a kindergarten teacher in Santa Cruz. This winter...
SHERI NACHT: I figured out that I had lice myself, which I haven't had since I was a child. It was a total nightmare.
HENN: Did you have to - you know, like, send a letter home to parents and explain that not only was someone in the class infested but in fact, it was you?
NACHT: I had the nurse come down and check my whole class. We found out that there was another little girl who had lice, so they went ahead and sent the letter. And it's just a letter saying somebody in the school has lice, and make sure to check your hair.
HENN: Even if it didn't name names, Sheri was mortified.
NACHT: I combed and combed, and shampooed and combed for three weeks, and had a friend combing my hair every other night. And we just - it was very difficult to get rid of, and I wasn't sure that I was done with it.
HENN: Turns out, she wasn't. And even researchers who study lice for a living, Ph.D.s in entomology, can become helpless when faced with a live, fertile louse loose on the scalp of their child.
DALE CLAYTON: My wife and I couldn't get rid of the head lice.
HENN: Dale Clayton studies co-evolution and parasites at the University of Utah. He's been doing research on lice for decades.
CLAYTON: And here I am, supposed to be an expert on lice - and there are not many of us in the world, by the way. ..
(SOUNDBITE OF LAUGHTER)
CLAYTON: ...completely clueless about how to get rid of human head lice.
HENN: When his kids were little, they - like millions of others - got it. And he spent weeks combing and picking and shampooing.
CLAYTON: Even then, it was already pretty well known that lice were evolving resistance to many of the shampoos that are available in drugstores and grocery stores and so on.
HENN: So it became Dale Clayton's mission to build a better louse trap.
CLAYTON: The first attempt was to take pigeon lice - and I'm not making this up - and put them in my hair, and then put on my mother's bonnet hair dryer.
(SOUNDBITE OF LAUGHTER)
CLAYTON: ...and look to see if it had any effect on them, if it killed them.
(SOUNDBITE OF LAUGHTER)
HENN: It didn't. First thing you should know about Dale Clayton is he is not, in fact, crazy. But he does know a lot about lice. For example, he knew that pigeon lice could never survive and breed on a human head. He also knew something else - that sudden changes in climate can kill these bugs.
When he moved his lab to Utah, from Oxford in England, something very bad happened.
CLAYTON: It's quite arid here. We couldn't keep lice alive on our birds, and we couldn't figure out why for a few months.
HENN: Turns out, lice get most of their moisture from the air. If you suck all the moisture out of a louse, you can dry it out, you can desiccate it; you can kill it.
Now, a bunch of dead lice may have been bad for Dale Clayton's research, but as a parent who was sick of nitpicking, he saw an opportunity. He imagined building a machine that could kill these annoying, little bugs by the thousands.
CLAYTON: We tried a bunch of different approaches to drying out lice.
HENN: He tried lots of different hair dryers - bonnets from beauty parlors and handhelds; he tried those wall-mounted hand blowers you see in bathrooms.
CLAYTON: We even tried a leaf blower.
HENN: Dale Clayton became a bit obsessed.
CLAYTON: At one point, we infested my kids with head lice - male lice only, so they couldn't breed - and treated them in the lab. They're in college now, but they like to tell that story to shock their friends.
HENN: Eventually, he and a team of engineers built the LouseBuster. It looks a little bit like your grandmother's old canister vacuum cleaner but instead of sucking air in, it blows hot air out. On the end of it, there's an attachment that looks a bit like an overgrown, plastic porcupine - 28 little nozzles that direct air along the top of a scalp.
Getting treated with a LouseBuster takes about half an hour, and it feels a bit like a heated head massage.
NACHT: And that was it.
HENN: It kills lice, and it kills their eggs - the nits.
NACHT: It's magic. It's amazing because nothing else kills the eggs.
HENN: Sheri Nacht says it may also have saved her sanity.
NACHT: If you can't kill the eggs and you don't find every last one of them, then you're starting all over again.
HENN: Today, Dale Clayton's company sells the LouseBuster to nurses, schools and hospitals, and it leases it to salons with names like Nitless Noggins and Hair Fairies. [POST-BROADCAST CORRECTION: One of the salons leasing the LouseBuster was misidentified. It is Hair Whisperers, not Hair Fairies.] Dale Clayton doubts this invention will ever make him truly rich, but it has allowed him to scratch that entrepreneurial itch.
Steve Henn, NPR News.