Why Do Cats Purr?

The phenomenon of purring has fascinated humans for ages. A lot of research has been conducted to figure out this feline mystique, but no one knows for certain why cats purr, though it is believed to be a voluntary act initiated by the central nervous system. In other words, cats purr on purpose, not just as an instinctive response.

Scientists report that cats produce purring sounds by using the diaphragm to push air back and forth across vibrating nerves in the larynx. Purring occurs in a frequency range between 25 and 150 hertz. At the lower end of the range, that rumbling sound can resemble an idling diesel engine, which has a similar velocity.

All domestic cats and most wild felids are are born with the ability to purr. Cats, from young kittens to senior citizens, purr when they are happy, such as when they are being petted, anticipating dinner, or snuggling on a warm, cozy bed. Mother cats purr when nursing their kittens, and kittens purr when nursing.

But many cats also purr when they are afraid or in pain. That helps explain why females may purr during labor and why some cats purr when they are being examined at a veterinary clinic or when they are recovering form an injury. The purring might serve to reassure or comfort the frightened cat, and some studies suggest that the low-level vibrations of purring physically stimulate feline muscles and bones to keep them healthy and actually hasten the healing process.

Excerpted from The Cat Behavior Answer Book (Storey, 2007), by Arden Moore.

228 comments

Dent H.
Dent H.2 years ago

Cats purr because they have a tiny little engines built into their chest. This tiny little engine help the cat pump extra air into their body so they can run faster. It also starts up and runs when they are happy. Some kitties have better mufflers than others and their little engine can be heard from quite a distance. Some have such good mufflers you can't hear them at all, but most of the time you can feel their little engine if you put your hand in just the right spot. All of us who love those little critters know this, but sometimes it is hard to convince others of kitties little engines. Some people think we are making it all up. Imagine that. Cats are cool!

Elena Echandi
Elena Echandi2 years ago

Uno de los grandes placeres de la vida es estar acostado con tu gato encima ronroneando!!!

wael a.
wael a.2 years ago

Thank you

Laura Saxon
.3 years ago

I love it when my cats purr.

Ewelina Grobelna
Ewelina Grobelna3 years ago

purring is one of the best sounds ever!

Terry V.
Terry V.3 years ago

and the final answer is ???

Sonny Honrado
Sonny Honrado3 years ago

Thanks.

Maureen Hawkins
Maureen Hawkins3 years ago

I've always suspected that kittens' purring while nursing pleasurably stimulates their mothers' nipples, thus further inclining her to nurse. The kittens' purring is rewarded by more milk, love, and comfort. Just as badly injured or dying humans may call for their mothers, I suspect a cat in pain is trying to recall (at least in her mind) that absent source of comfort by purring.

Maureen Hawkins
Maureen Hawkins3 years ago

I've always suspected that kittens' purring while nursing pleasurably stimulates their mothers' nipples, thus further inclining her to nurse. The kittens' purring is rewarded by more milk, love, and comfort. Just as badly injured or dying humans may call for their mothers, I suspect a cat in pain is trying to recall (at least in her mind) that absent source of comfort by purring.

Lisa S.
Lisa S.3 years ago

My cats purr a lot, so hopefully I am making them happy =^.^=