Cats seem to purr for several reasons and in a variety of situations. Some experts believe that the original function of this sound was a way for kittens, while nursing, to let their mother know that everything was okay or that they were content. In a sense it was meant to reassure, and the mothers would often reassure the kitten in return by purring back.

ith your cats, you'll likely find that when cats purr it can mean different things. Many cats purr when they're content, such as when they're being petted. Others purr at other cats as a sign of playfulness or friendliness. And there are those who purr when they are distressed, sick or injured, which may be a way for the cat to calm himself. Either way, purring is purr-fectly normal behavior for cats.