Bruce Young, Ph.D., of the A.T. Still University of Health Sciences, has dedicated his career to understanding the incredible, bizarre, and sometimes-hilarious world of snake noises. He spilled his ssssecrets to mental_floss in a recent interview.

1. SNAKES GROWL.

Young was still an undergraduate the first time he heard a king cobra growl. He’d gotten a job as “glorified bait” in a venomous snake show in the early 1980s, keeping the snakes distracted while a presenter spoke to the audience. Standing on its tail, the fifteen-foot king cobra was taller than the college sophomore. The snake swayed toward him, mouth open, making a sound, Young says, “like an angry German shepherd.”

Faced with a ticked-off king cobra, most people would lose it, but Young fell in love. He realized that nobody was researching why or even how snakes make noise. 

2. THEY SHRIEK.

Young started by trying to understand the basics: how snakes hiss, why they do it, and why all hisses sound pretty much the same. Most snakes make some kind of noise, whether it’s hissing, rattling, or rubbing their scales together to make a dry, raspy sound. 

Some snakes make weirder noises than others. Young discovered that, uniquely among snakes, the pine snake (Pituophis melanoleucus) has a vocal cord. As a result, P. melanoleucus's hisses and bellows have a shriek-like quality.

3. THEY FART IN SELF-DEFENSE.

Snakes are pretty intimidating as it is, and most of their noises serve to make them seem scarier. (That’s what they’re for, after all: to scare off predators.)

But then there’s the farting. Young found that, when cornered, snakes of multiple species produce popping sounds by forcefully pushing air out of vents in their back ends. “It’s basically snake flatulence,” Young says.

Like growling or hissing, the fart noises are intended to be scary. And who knows? For a non-human predator, they might be.

4. HELIUM IS THE GREAT EQUALIZER.

Again and again, Young’s research returned to the growl of the king cobra. How, he wondered, can a snake even make a noise like that? After dissecting a bunch of preserved cobras, Young thought he had an answer. 

As any bored bar-goer knows, you can make all kinds of noises by blowing across the top of a beer bottle. Young found a number of little sacs in the trachea of the king cobra. If, he theorized, the snake was pushing air across the openings of these empty sacs, the resonance would make a low rumbling sound.

The pitch of resonant noise depends on the gas being used. Young decided to test his hypothesis by—what else?—dosing a bunch of king cobras with helium.

“I got some large king cobras, put them in a room, got them very agitated, and recorded their growls,” says Young. Once he had a baseline, he gave them helium. The theory held. Helium immediately changed the pitch of the snakes’ voices, and Young was left with “big, writhing, angry king cobras … growling like Mickey Mouse.”

5. SNAKES CAN HEAR JUST FINE.

“The biggest misconception about snakes is that they are deaf,” says Young. At certain frequencies, he says, they can actually hear better than house cats can. Sound waves travel through the muscles and bone in their heads and vibrate against their inner ears.

This doesn’t mean that snakes talk to each other. The noises they make are almost always at a frequency that other snakes can’t hear. Young says the best candidate for a snake-audible, snake-produced noise is the growl of the king cobra, which rumbles at a very low frequency (when Young and his helium tank aren’t around, that is). 

6. STAYING SAFE IS EASY—JUST BACK AWAY.

“Almost all of the snake sounds we know of are made in defensive interactions,” says Young.

In other words, if you hear a snake making a noise, “it’s only because you scared it. Leave the poor thing alone.”

All audio files are courtesy of Young, who notes, "You can sometimes hear bumps as I try to dodge an angry snake."