Air Date: Week of July 10, 1998

Hissing, spitting, and an occasional growl. These are the sounds that snakes usually make to get their message across. But how snakes make these sounds is more of a mystery. Bruce Young, an assistant professor of biology at Lafayette College in Easton, Pennsylvania studies the how's and whys of snake sounds. Professor Young took producer Peter Clowney on a tour of his multi-roomed laboratory, beginning with the venomous snake room.

Transcript

CURWOOD: A hiss, a spit, an occasional cobra growl. These are the sounds that snakes usually make to get their message across, but how snakes make the sounds they do is more of a mystery. Bruce Young, an assistant professor of biology at Lafayette College in Easton, Pennsylvania, studies the hows and whys of snake sounds. Professor Young took producer Peter Clowney on a tour of his multi-room laboratory, beginning with the venomous snake room.

(Machinery humming; voice echoes)

YOUNG: The signs out here just make it clear what is in this room. It simply shows a gentleman who was bitten on the back of his hand by a spitting cobra. You can see that he is now missing much of the top of his hand, and indeed much of the skin over his forearm, that can probably never really be repaired. It's simply a reminder, this is not a casual, relaxed place.

(A key turns in a lock)

YOUNG: Let's just make sure everyone's where they're supposed to be. Yeah. Now, unfortunately, although this is a little uncomfortable, the room is full of spitting cobras, which can blind you. So you need to put on goggles before you can go in.

(The door opens. Shifting and hissing sounds)

YOUNG: Oh, don't get yourself tied up in a knot.
I've been working with these animals for 17 years now. I have never been bitten by a venomous snake, and I have never had a snake escape. And I have very strong motivation to keep that record alive. (Laughs) Yeah, this would be a nice cross-section. (Moves items.) All right, cover them up with blankets so we don't alarm anyone in the hallway.

(A new, quieter room)

YOUNG: This is my research lab. We have kind of a research platform that's right beside my computer. What we'd really be doing is turning the snakes loose here on this recording platform and coupling the microphone directly to the computer. As you can see, around the work table, we've put up this little plexiglass barrier. That means even if we do get a little too close and they strike, they're going to hit the plexiglass. In fact, you can see from all the venom over it that it's earned its keep. (Some clanking sounds)

We're going to start with an Eastern hognose snake. It's kind of a real beautiful dark green and black with a series of yellow bands or blotches on it. You'll see, he'll rapidly flare out the back of the head. He winds it, now he'll start making noise as well. (Hissing sounds)

That was a very nice series of couplets, which you can hear is first the snake hissing while he's exhaling. There's a little pause. Then he hisses while he inhales, and there's another pause. You can actually small, now, I don't know if you can pick it up, there's a little bit of a musk. Which is another fairly common defensive behavior in snakes. They've got some special glands back at the base of their tail that release a variety of scents, especially as kind of alarm or warning scents.

All right. Let's put him back. (Clanking sounds)

This is a North American pine snake. The only snake that has a vocal cord. And so, what happens is when they hiss, which they do with their mouth open, it produces a very distinct kind of shrieky, rasping sound.
(Hissing, then clanking sounds)

Now the next snake I want to show you is really dramatically different to all of these. (More clanking sounds) Both in appearance and in the sound he makes. This is an absolutely gorgeous little snake called a Sawskill viper. This one actually isn't so little; it's almost two and a half feet long. You can see it has kind of a nice pink, almost a pale scarlet color. And the interesting thing about him, if you look at him, you can see his body appears to be kind of rather rough or jagged looking. The scales of this snake are different than a typical snake scale. They're held at different orientations and are larger, and you can hear just why that is. Because unlike all the other snakes I've shown you that hiss, this snake produces noise by simply rubbing his body scales together. (Scales rubbing) You can see watching him that this particular species is really prone to biting. They're not a particularly easy snake to keep (hissing continuing from scales rubbing. More clanking)

See if this snake will perform for us. This is Russell's viper, which may have the distinction of killing more people than any other snake on earth. Estimates range of over 15,000 people a year. The reason I have them is you can hear. (Hissing sounds) They produce an incredibly loud sound. (Loud hissing) What we think is going on is that his nasal passageway ends up being built almost like the end of a trumpet. So you have this distinct flare to the end that allows him to really amplify the sound.

Now, what's coming up is undoubtedly the rarest sound produced by snakes. I'm going to play for you the sound of a Sonoran coral snake, and when these snakes get agitated they actually expel air from the end of their digestive tract, their body opening called the cloeca. (Sound like a duck quack)

No matter what it sounds like this is not the equivalent of snake flatulence. There's no material expelled from the digestive tract, and the sound is only produced if the snake's head is held and his body is pinched. So it's truly a defensive sound. (Sonoran coral snake sound continues.) One of the simple explanations for why snakes don't talk, quite simply, is they're making sounds they can't hear. (To snake:) Oh, settle down, now you've been so good.

CLOWNEY: You know he doesn't listen to you, and yet you speak to him anyway.

YOUNG: I talk to all of my snakes. And yeah, it makes absolutely no sense (laughs).

CURWOOD: Professor Bruce Young talked to his snakes with producer Peter Clowney.

YOUNG: All right, guys, come on. (A door opens) Let's go home.