We already have “hung like a horse” to describe a particularly well-endowed human male; now maybe we need “always hard like an alligator.” Admittedly, it doesn’t exactly roll off the tongue…and really, if a human man’s penis were hard as often as an alligator’s, it would be classified as a medical condition. And that is because alligators are always hard.

Yes, as if alligators weren’t intimidating enough with their razor-sharp teeth and lethal, muscle-bound tails, they’re also permanently erect. (As a reptile enthusiast, I must add that alligators do not naturally hunt humans and only attack when harassed or have previous experience eating human food. Okay, moving on.)

Now it’s not quite as obscene as it sounds. Male alligators aren’t lounging on riverbanks, constantly showing hog. Instead, their penises are hidden inside their bodies and only spring out when needed. Sort of like a pornographic jack-in-the-box.

According to a 2013 study, male alligators’ penises are made of tough, fibrous tissue and shoot out for procreation before being retracted at the same speed.

“It is really interesting and really bizarre, very different from anything we’ve seen in vertebrates,” study author Diane Kelly told Live Science.

Prior to this study, scientists knew next to nothing about the mechanics behind alligator mating. So, to answer this burning question for all of us, Kelly set out to learn more.

After dissecting a truly enormous 13-foot (4-meter) Louisiana gator, she found a nearly 2.75-inch (7cm) long penis inside its cloaca, an alligator’s waste and reproductive orifice.

Alligator PENISES Don’t Get Hard, They Stay Hard

This unusual find only became stranger when she realized its penis was filled to the brim with collagen, a fibrous protein that acts as scaffolding in your body. Injecting it with saline fluid to produce an erection yielded no results.

“I tried it with the alligator and I got no length change, I got no diameter change. I got nothing,” Kelly explained to Live Science. “It became very clear to me right then and there that there was something very different.”

That’s when she discovered that an alligator penis doesn’t inflate like a human’s; it simply…stays ready. By pulling on the tendons near the cloaca, she caused its penis to spring out. “As soon as those muscles relax, the penis gets whipped back into its original position,” Kelly said.

So, there you have it. It’s literally impossible for an alligator penis to be flaccid. Now have some respect for the closest living relatives of the dinosaurs. (Birds, which are dinosaurs, are another conversation entirely.)