IRA FLATOW: This is Science Friday. I’m Ira Flatow.

We’re going to now talk about– bring on one of our favorite, favorite guests for the hour. You probably know who she is. The modern military is full of high tech machinery and science.

And Mary Roach has written a new book called, Grunt, the Curious Science of Humans at War. You may know her other books like Gulp and Stiff.

As I say, the military has an entire department devoted to developing new technologies. And Mary Roach looked at a different category of gear. Not the big armored tanks or the F35s doing flyovers. But the more personal, individualized equipment.

She wanted to know how do we protect soldiers from things like exhaustion, disease, and panic. Hazards that civilians may not think about.

One of the major hazards of combat that she investigated was diarrhea. Yes. You heard me right. It’s something everyone has dealt with. Now imagine that, combined with a 95 pound rucksack slung on your back while crawling under enemy fire.

And diarrhea falls squarely, so to speak, into the wheelhouse of my next guest, for whom there is no detail too stinky, too gross, or intimate for her to explore. Mary is author of the new book, Grunt, the Curious Science of Humans at War. You may know over from around the books Gulp and Stiff.

Welcome back to Science Friday.

MARY ROACH: Well, thank you Ira. I’m just giddy to be back.

IRA FLATOW: I hope I did you justice in speaking dirty like that.

MARY ROACH: Oh, you did. You summed me right up.

IRA FLATOW: Well, you write about, you say I’m interested in the parts no one makes movies about. Not the killing, but the keeping alive.

MARY ROACH: That’s exactly right. Yes.

IRA FLATOW: And where did you get the idea for this book then?

MARY ROACH: This book, the idea came from– it’s kind of an odd path. I was reporting a story in India on the hottest chili pepper in the world. Arguably the hottest chili pepper in the world, the bhut jolokia.

And while I was there, somebody said, well, the Indian defense ministry weaponized this chili pepper. And I thought I needed to look into that.

So I went over to this lab that worked on a lot of different projects for the Indian military. And that was where I came to realize this might be a Mary Roachable topic.

They were working on a leech propellant while I was there. They were just about to be heading out into the river and rolling up their trousers and attracting the leeches and then repelling them. And I didn’t get to report on that. But that’s what got the gears turning.

IRA FLATOW: Our number is 844-724-8255 if you’d like to talk to Mary. 844-724-8255. You can also tweet us @scifri, S-C-I-F-R-I.

What about military technology interested you? I mean you’ve written about all kinds of stuff.

MARY ROACH: Well, it wasn’t so much the– well, the technology that– the technology that deals with the human body and keeping it in working order. Because it’s all the things that we ordinary individuals deal with at a certain level, like just ordinary heat and ordinary sleep deprivation. People in the military are dealing with an intense load of it.

Whether it’s sleep deprivation, or heat, or what your carrying, or flies in the desert, or you name it. It becomes enough of a burden that there’s a science dedicated to trying to mitigate the effects of it. And there’s all kinds of interesting labs and places to investigate.

IRA FLATOW: Now, let’s go into some of that. You have– there’s something called a chicken gun that you talked– that you write about that test bird strikes and fighter jets.

MARY ROACH: Yeah. The chicken gun. I was attracted to that simply by the name, the chicken gun.

And it is kind of what it sounds like. It’s a piece of heavy artillery that fires supermarket chickens at jets or airplanes, particularly– well, not just the wind screen. But that’s an issue if a bird smashes into the windscreen the jet or plane can come down. It could also go into the engine.

Anyway, the chicken gun was just– it’s how I set up the book because it’s just an example of how unexpected military science can be. Just these little bursts of heroics that nobody hears about. Somebody who invent– someone invented and researched the chicken gun.

And also, I mean the chicken wasn’t an obvious choice because chickens don’t fly and they’re denser than birds that fly or float around the wetlands around the airports. So there was all these papers going back and forth on, what kind of bird should we use? And should we make an artificial bird? And what about the situation where we’ve got this big chicken, but sometimes there’s a smaller bird that may pierce the windscreen. And then somebody actually coined the phrase, the feathered bullet phenomenon.

And anyway, just this whole world of science going on under the radar with the hope that it will keep planes from going down.

IRA FLATOW: Is this a frozen chicken? Or one–

MARY ROACH: Frozen and then thawed, yes.

IRA FLATOW: So you’re not shooting a frozen chicken still in a hard shape?

MARY ROACH: No. It’s thawed. It’s thawed.

IRA FLATOW: Do some kind of damage with a frozen–

MARY ROACH: Exactly. That would be definitely a worst case scenario. This is probably highly unlikely that a pilot will hit a frozen chicken while flying.

IRA FLATOW: Just as you say that, you know, we’re– anyhow, you have a fascinating, I think, a really fascinating section on maggots. Using maggots to treat wounds, you know. Your point– it’s not a new idea. But using it now, there are considerations like what is the insurance reimbursement for a round of maggots.

MARY ROACH: Exactly. I have– in the book, I have the Medicare reimbursement number for maggots.

IRA FLATOW: There is one.

MARY ROACH: There is one. I don’t have it on the tip of my tongue, but it’s in there. And also maggots are– they’re prescription only, I have to say. And they are an FDA approved medical device, maggots.

And you order them– your doctor can write out a prescription. There’s a place, Medical Maggots, in Southern California, that will ship them out. And the dosage requirements are right there.

And there’s a little cage dressing to keep the maggots from straying. Because you don’t want big fat maggots wandering out, pupating, becoming flies in a hospital setting. That’s not good.

IRA FLATOW: Yeah. I hate when that happens. Tell me how you dress– how do you dress a wound with maggots? What’s the process when– you know. Give me a little inside information here.

MARY ROACH: Sure. It’s a dual flap cage dressing. It’s essentially a dressing that keeps the maggots in place. But it has to be– it’s sounds like fairly simple, slap on the dressing. Let the maggots debride.

What they’re doing is debriding a wound. They selectively dine on dead tissue, which is very good for healing. It promotes the regrowth of fresh, new tissue. So that’s an excellent thing. They fight infection.

But the trick with maggot therapy, you need to replace the maggots every couple days. Because then when they start to grow, they reach a point where they want to leave the wound, go off, pupate, and become a fly. So the dressing has to be changed. And you need nursing staff trained to change the maggot dressing.

And there’s some resistance in some hospitals. It’s not a terribly pleasant chore. But it’s very effective.

And it’s used a lot in, specifically, in diabetic populations. There are foot ulcers that it’s very difficult to get them to heal sometimes. And then the maggot therapy has been very effective with them.

It’s in the book because in World War I was one of the first times that this was discovered. I mean ancient, if you go way, way back in ancient writings, there are some mentions of it.

But in World War I, William Baer, who was a surgeon in the French expeditionary force, noticed these wounds. These soldiers came in with these wounds that were infested with maggots. And of course, everyone was horrified and wiped them all out, washed them out. And then underneath, he saw this fresh, pink, very healthy tissue. And the gears began turning in his head.

And he thought let’s– some years later, he actually experimented in a civilian population. And things went very well. And things have continued to go well with maggots.

IRA FLATOW: How do your patient’s react? I mean you have a battle hardened soldier coming in with a wound and you’re offering a maggot dressing. Is there’s some resistance?

MARY ROACH: Well, among the more commonly– and the diabetic population where it’s more commonly used, I asked him about this. I mean it’s a– I mean maggots are– it’s a disturbing image. I mean don’t ever look up myiasis on Google Images. Myiasis being the infestation.

IRA FLATOW: How do you spell that?

MARY ROACH: I’m not going to tell you.

Anyway, it’s a– and I asked one of the doctors who treats diabetics with this. And I said, how do they feel about this? Aren’t they– are they horrified? Is there a lot of resistance? He said no because the alternative is this wound that doesn’t heal, possibly amputation.

And he said something about when you put the maggots into the wound, they kind of get involved. And he referred to them, they get involved with the little guys and gals. And they come– there’s a fondness for the maggots.

And I have to say, having been introduced to a dish full of maggots in some raw liver with a military entomologist named George Peck, he took one out. He put one on my finger. It’s the size of a cupcake sprinkle.

They’re kind of cute at that age. They’re not the big, fat ready to go pupate. They’re little and they’re like inch worms.

Anyway, but the patients get into it to the point where this company makes t-shirts that say, maggots on board. That people can proudly wear when they’re going around with their maggots in the little cage dressing. So it’s– I think there’s an appreciation for the healing that’s going on in their body. And so they have a very different take on maggots than you or I might.

IRA FLATOW: Be proud of your maggots. Our number, 844-724-8255.

There has been a history of developing military grade stink bombs. Were these actually deployed stink bombs?

MARY ROACH: Yeah. Well, the– not the mother of all stinks. It wasn’t actually a bomb. But it was a paste or a spray.

And it was something that the Brits started out, stench liquid. And then the OSS, the precursor to the CIA in World War II, got wind of this idea. And wanted it to be this little subtle secret weapon that resistance groups in occupied nations could spray onto the uniforms of officers. When they’re out in public you would sidle up and sort of spray this thing.

And it was a foul smell. And it also had this compound that would delay the onset of the odor, which would enable the operator to escape before the smell hit. And so they wouldn’t get caught.

So there was a lot of thought that went into this little tube of stench. And the nickname for the substance was, Who, Me? Because originally it had kind of a fecal smell. And it has morphed over the years to become various other scents.

Anyway, but there was a whole file in the OSS archives on Who, Me? And it’s amazing. There were specs for it. Like it has to be lastingly penetrative at 70 degrees Fahrenheit for two hours. It has to withstand dry cleaning fluid or rain water.

There can be no backfire. And matter of fact, there was some backfire and dribble that caused all manner of woe to the operator.

So that was the original stink weapon. And then over the years there’s been work that went on all the way through the ’90s in developing nonlethal malodorants. Not for humiliating officers, but for clearing a room or dispersing a mob.

Just a nonlethal weapon, alternative to a tear gas. Something that smells so vile that you can’t be in the room with. And believe me, that’s not been exaggeration.

IRA FLATOW: You’ve smelled it yourself?

MARY ROACH: I’ve smelled a number of them. The mother of all malodorants, Stench Soup, which was developed at Monell chemical Senses Center, is a kind of a crafty mixture. It starts out with something that was deemed through research to be the most universally loathed and upsetting smell, and that is US government standard bathroom malodor.

That was a compound that was developed for testing latrines deodorizers. So they needed a consistent simulated latrine smell. So this exists as something you can purchase even today.

And they started with that at Monell. And the really sly part is that they added a top note kind of floral, fruity, lovely scent. So that when you come near and you give that first tentative sniff, like what’s going on? What is this? You’ll be encouraged then by the lovely smell to take a deep keeper inhale, as it’s known. The keeper inhale then being the wall of absolutely horrible US government standard bathroom malodor.

So it’s a mixture of the bathroom smell and the floral fruity created an element of mystery, which is also effective. Because when a smell isn’t identifiable, it’s more frightening. So it’s not only repugnant, it’s also scary.

Like I don’t know what that is. It might be dangerous. So people tend to want to get away from it.

IRA FLATOW: Talking with Mary Roach, author of Grunt, the Curious Science of Humans at War, on Science Friday from PRI, Public Radio International.

We have a few folks who– well, let me go to the phones and see if we can let them ask themselves. Let’s go to Mark in Birmingham, Alabama. Hi, Mark.

MARK: Hello. Mary Roach, it’s a pleasure to speak with you. I’ve been a fan of your writing for many years.

MARY ROACH: Hello, Mark.

MARK: And I’m very interested– Hi. I’m really interested to know how it is that you came to be interested in such obscure and interesting parts of science. Was it something in your upbringing, your college education?

You and I had actually overlapped at Wesleyan and we didn’t know each other. I don’t think.

MARY ROACH: Oh. Go Wes.

MARK: Yeah. So I’m just wondering how do you embark on such a fascinating and off– sort of offbeat writing career?

IRA FLATOW: OK. Thank you.

MARY ROACH: Yeah. Kind of– yeah. Thanks, Mark. Kind of randomly. I was writing sort of as a general journalist magazine feature writer. And someone at Discover Magazine, an editor at Discover Magazine contacted me and encouraged me to do some stories for them. So that got me into the realm of science.

And I don’t know what it is about me that causes me to wander off into the kind of curious fringes of the human body and science. I’m not I’m not really sure. Yeah. I don’t know. I don’t think there was anything in my childhood.

My mom was very kind of straightforward and out there with her– the things she would refer to about the human body. I remember her just– yeah. We don’t even need to go there. But she–

IRA FLATOW: But you write a lot about bodily functions in all your books.

MARY ROACH: I mean, should I say this, Ira?

IRA FLATOW: Sure. Go ahead.

MARY ROACH: There’s no dirty words. OK my brother reminded me recently, I’ve never shared this on radio. My mother’s no longer with us so she won’t be horrified. But my brother reminded me, because he just read the book.

And he said, remember that time when mom said– and this is an old-timey medical term. It’s some kind of a growth. But anyway, she said to him in particular, yes. I have a wen on my vulva.

A wen is some sort– I’m not sure exactly what it is. You don’t want a wen anywhere. But I think you particularly don’t want a wen on your vulva.

But that’s the kind of thing my mom would just blurt out. I don’t know. She would just say– she was very casual in her references to kind of disturbing bodily–

IRA FLATOW: So the apple doesn’t fall far from the tree, in this case. You say those things but you’re paid for it.

MARY ROACH: Yeah.

IRA FLATOW: Stay with us, Mary. We’re going to take a short break and come back and talk more with Mary Roach, author of Grunt, the Curious Science of Humans At War. A terrific book in the series that Mary writes, all her books.

Our number, 844-724-8255. You can also tweet us @scifri. Stay with us. We’ll be right back after this break.

This is Science Friday. I’m Ira Flatow. I’m talking this hour with author Mary Roach about her new book, Grunt, the Curious Science of Humans at War. And you can read an excerpt from her book at our website. It’s sciencefriday.com/grunt.

Mary, you talked to Mark Riddle, who was running a clinical trial about better diarrhea treatments. What’s he like? What type of personality does it take to run a study about diarrhea? Must take some– a unique person.

MARY ROACH: Mark is a delightful combination of very funny with a great sense of humor about the topic. like, for example, when he’s trying to recruit people– this is Camp Lemonnier in Djibouti. When he’s on base trying to recruit people, he put a bunch of signs on the backs of the bathroom stall saying, got diarrhea?

So anyway, he has a good sense of humor about it. But he’s also so serious and so dedicated to the topic that he will say things like, I live and breathe this stuff. Not meaning anything, like not having any idea how that sounded. Just, you know, he’s that dedicated. He I learned a lot–

IRA FLATOW: Do you know that you say that kind of stuff, too? During the conversation you’ve dropped–

MARY ROACH: What did I say?

IRA FLATOW: I got wind of this, or I– that sort of stuff.

MARY ROACH: Do I say that?

IRA FLATOW: Yeah. You said today.

MARY ROACH: I did?

IRA FLATOW: Yeah. I let it go by. But I think that if you’re around writing about this enough times, the puns just come out naturally, right?

MARY ROACH: I did not say that. Yeah. OK. Wow. You got me.

I guess I probably– yeah. I probably do. Anyway, I got him on that one.

IRA FLATOW: I feel like I’m in an Annie Hall moment here.

MARY ROACH: Yeah. He– anyway, Mark is great.

Mark was so good natured because he– one of the conditions for I going to Camp Lemonnier is that I had to be escorted all the time. And I thought that meant that once I get there, they’ll let me wander around. But No. Every waking hour I was shackled to Mark Riddle. Or rather, he was shackled to me. So it’s good that we got along because I was there from the though they played the Djibouti national anthem in the morning to lights out in the evening.

So anyway, but he’s– he cares a great deal about it. He’s involved with efforts to create a vaccine for ETEC, which is a particularly nasty form of E. coli and Verotoxigenic E. coli. It’s kind of similar in the way it works to cholera. And it’ll be great to get a vaccine for that because half a million people die still every year, mostly in developing nations, from this.

IRA FLATOW: You talk a lot about– these are real heroes that no one hears about because they’re saving the lives of all these soldiers.

MARY ROACH: Yeah. Soldiers and also in the civilian sphere as well. Yeah.

IRA FLATOW: Do they– we give medals out for all kinds. Do these people get any kind of medal or recognition for all that work they do?

MARY ROACH: No. They have to make do with a Mary Roach book. They don’t get– that’s what they get.

No. They should get a– there should be some kind– I mean, there may be. I think there are meritorious civilian awards that the military hands out. But there’s one woman in the book who does work with making vehicles safer. And she got that award.

So some– yes. There are awards that are bestowed. But not as many as there should be, perhaps.

IRA FLATOW: Let me see if I can take a quick call before we have to go, to Andy in Charlotte, North Carolina. Hi, Andy.

ANDY: Hi, good afternoon.

IRA FLATOW: Hi there.

ANDY: How are you doing? Mary, I love your stuff.

I work for a fragrance company called ScentAir. And we do work with the US military on fragrances, scents for simulators. Because there’s a lot of research that the soldiers that are going over to Iraq and Afghanistan, you can do realistic simulation of the data type of environments they’re going to get into. But if there’s no scent, you don’t have the right fear or flight reaction.

MARY ROACH: Yes.

ANDY: So I was curious if you did any research on that or if you had come across that.

MARY ROACH: Yes. To be real quick, I know you’re wrapping up, Ira. But yes.

There was a strategic operations, this group that does simulated combat to train medics and Navy corpsman who do care for the Marines. And one of the things that they used, they could probably use your product, because what they were using in the case of evisceration or guts coming out, they used a product that I probably can’t say on the air, liquid– blank blank.

But that’s just to create– I mean, that’s what it would smell like if the guts were torn open. Anyway, so yeah. That that’s part of creating the every sense. The noise, the visuals, but even the smell. So yeah. Yeah.

IRA FLATOW: Well, Mary, it’s another great book in your series of letting us know more than that we’ve known before about stuff that we think we should care about. The book is called Grunt, the Curious Science of Humans at War. Covers everything including stuff about camouflage, and fashion, and stuff like that, it’s all through the book, and tanks, and armor. It’s a great book Mary, as usual.

MARY ROACH: Thank you, Ira.

IRA FLATOW: Thanks for taking time to be with us today. And good luck with your book.

Mary Roach, you can read an excerpt from a book on our website at sciencefriday.com/grunt.

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