The purr, a soft vibration that housecats make as they breathe in and out, is unique to cats and cat-like animals. Cougars, cheetahs and a few other big cats purr, too; so do civets, genets and mongooses. But why do cats purr?
“It’s one of those behaviors that we mostly understand, but not totally,” said Mikel Delgado, (opens in new tab) a certified cat behavior consultant at Feline Minds, told Live Science. “Purring is likely reflexive, like breathing.”
