SCOTT SIMON, host:
Now, for women who are listening, we have a story that will take you to some places that you're usually not allowed to go. As for men, all we can say is: this is something you know, even if you never talk about it. Breaking the silence, our science correspondent, Robert Krulwich.
ROBERT KRULWICH: May, can you hear me?
Professor MAY BERENBAUM: Hi. Yeah, can you hear me?
KRULWICH: Yeah, I can. Oh boy. Okay. My friend, Professor May Berenbaum, studies insects at the University of Illinois, and she has a friend.
Prof. BERENBAUM: My colleague, Arthur Zangerl - Z-A-N-G-E-R-L.
KRULWICH: Is this the guy who goes to Holland to study wild parsnips?
Prof. BERENBAUM: Yeah, exactly.
KRULWICH: Okay. So while Arthur was passing through the airport looking for the parsnips in Amsterdam, he saw something in the men's bathroom.
Prof. BERENBAUM: Yeah.
KRULWICH: The urinals? What is that...
Prof. BERENBAUM: That each urinal had a little figure of a fly. It looked - a very realistic fly.
KRULWICH: So it's a picture of a fly engraved into the porcelain.
Prof. BERENBAUM: Exactly. Yes. It looks very realistic.
KRULWICH: And where was it?
Prof. BERENBAUM: Just to the left, I think, of the drain.
KRULWICH: Well, why would they put a fly to the left of a drain?
Prof. BERENBAUM: I'm not an expert on urinal structures.
KRULWICH: No problem. I found an expert.
Professor RICHARD THALER (University of Chicago Business School): So, I don't remember when I saw my first fly in the urinal, but...
KRULWICH: To be fair, Richard Thaler is not really a urinal art expert; he's a professor of behavioral finance at the University of Chicago Business School.
Prof. THALER: Yes.
KRULWICH: And he's noticed that fly-bearing urinals are now showing up in more airports and more schools, in more football stadiums all over the world.
Prof. THALER: They have been spotted in Moscow and Singapore, JFK...
KRULWICH: In the new terminal in JFK.
And the reason, says May, is because when you emblazon a fly into a urinal, that fly changes human behavior. Or at any rate, the behavior of human males.
Prof. BERENBAUM: Having a target - let's see, how do we say? Reduces spillage.
KRULWICH: Spillage, yes. That's the term. And spillage in this case would mean what, in the most delicate way you can muster?
Prof. BERENBAUM: Misdirected stream?
KRULWICH: Misdirected stream, huh. Why would a fly engraving cause men to redirect their stream?
Prof. BERENBAUM: Apparently there is a deep-seated instinct to aim at targets in males.
KRULWICH: Okay, Richard, you're a male. You agree with her?
Prof. THALER: Well, sure, you know.
KRULWICH: But doesn't everybody? Certainly everybody with boys knows this. Julie Power, for example, co-founded a blog called Mothers to Work. And she has boys...
Ms. JULIE POWER (Mothers to Work): Two boys.
KRULWICH: Is misdirected stream a problem in your home?
Ms. POWER: Yes, it is a problem, Robert, I have lived with, yes.
KRULWICH: But in your blog you said you kind of have dealt with the problem, at least for a while.
Ms. POWER: What I did was I took a big - I took a red Sharpie and I wrote aim in big red letters on the toilet.
KRULWICH: You mean in the bowl?
Ms. POWER: In the bowl, on the back of the bowl.
Ms. POWER: A-I-M, like aim here. And then I did a big red circle around it.
KRULWICH: And will the boys aim at the circle?
Ms. POWER: Yes, they will aim, yes.
KRULWICH: So a fixed target is the key or...
Prof. THALER: Another friend of mine claims that Cheerios are really perfect. You throw one in the middle of the bowl and the boys will aim.
KRULWICH: Or for the older boys, there's the middle of the night option.
Mr. DOUG KEMPEL (Urinalfly.com): Men evidently hate to turn on the light at night because it blinds them, for whatever reason it is.
KRULWICH: That's why Doug Kempel, who runs a business called Urinalfly.com, is about to launch what he calls...
Mr. KEMPEL: Glow-in-the-dark fly.
KRULWICH: Glow-in-the-dark fly?
Mr. KEMPEL: That's right.
KRULWICH: Drawings you can paste into the toilet and because they glow, you know where to go.
Mr. KEMPEL: Yes, that's correct.
KRULWICH: But what I don't get is, why is it always a fly? I mean, why not a duck or why not a mammal?
Mr. KEMPEL: I don't know. What do you want to pee on? That's kind of the big question.
KRULWICH: Well, somebody must've decided that flies have a special attraction.
Prof. THALER: I think that the Amsterdam guy really started it. And apparently he's an economist.
Mr. AAD KEIBOOM (Deputy Director, Schiphol Airport): No, no, no.
KRULWICH: No, no, no. The man who invented etching flies into urinals was not an economist, says Aad Keiboom, deputy director at the Schiphol Airport in Amsterdam. The guy was named Jos Van Bedoff. He was a maintenance man at the airport, and he died in the early '90s. But he got the idea when he was a kid way back in the '60s.
Mr. KEIBOOM: Yeah, when he was in the army for his military service.
KRULWICH: As a soldier, he would, as soldiers often do, go the bathroom.
Mr. KEIBOOM: Then he noticed one day that someone had made a dot in the urinal, just a small dot.
KRULWICH: But because of that dot, that bathroom was much, much cleaner. So years later he kept that thought in his head and proposed, well, not a dot but a teeny fly. The airport adopted his idea and it worked fabulously.
Prof. BERENBAUM: Eighty percent. Spillage on the men's room floor was reduced by 80 percent.
KRULWICH: Wow. Is that right?
Mr. KEIBOOM: Oh, yeah, yeah.
KRULWICH: Yeah, but why did he choose a fly? 'Cause that's your act of genius right there.
Mr. KEIBOOM: Because his idea was, and that's what he told me, that that is the animal where men would like to aim for. And if you have him, then you have him really good then he can't fly away anymore. So that's why he came up with the fly.
KRULWICH: So guys like flies because we can't beat flies. Well, says May Berenbaum, maybe, but then how do you explain that 100-plus years ago in Britain they put a very different insect into their bowls - with a stinger?
Prof. BERENBAUM: In the late 19th century, in fact, Victorian urinals often had little pictures of bees. And this is hilarious if you're an entomologist, because the scientific name, the genus name, of the honeybee is Apis.
(Soundbite of laughter)
KRULWICH: Some things just can't be explained.
Robert Krulwich, NPR News.
SIMON: If you want to see the etched flies at the JFK Airport or the fly decal, they await your inspection on our Web site, NPR.org.