Chalk up one more for the roaches.

Not only are they nigh indestructible, but they also appear to have an enviable skill: growing bigger testicles. A new study reports that Madagascar hissing cockroaches can specialize as either “lovers” with big testes or “fighters” with large horns.

And true to their name, these roaches do hiss—whether they’re loving or fighting. “They have a short hiss when they’re startled,” says University of Nottingham biologist Kate Durrant. There’s a louder, more aggressive hiss when they fight. “Then they’ve got a third hiss when they court a female, and it’s this long, slow ‘ssssssssss,’” she says.

As sexy as that sounds, the males often have to battle before they get the chance to woo