Why Do Cats Purr?

We love to hear our cats purr. There is nothing better than a cat curled up on your lap, satisfied and happy, but have you ever wondered just how cats purr and why they do it?

Humans smile, dogs wag their tails and cats purr. All of us show our contentment in different ways. So it’s not surprising that when your cat is curled up beside you, or you are stroking them, they express their feelings by purring. However, purring is not always a sign of happiness. Sometimes it is an emotional response, indicative of pain or distress. Indeed, cats may purr while giving birth, so purring is more likely to be a mechanism that helps cats rest and repair.

Purring may be feline self-comforting behaviour. It is first expressed when kittens are only a few days old, perhaps signalling their presence to their mother, encouraging her to feed them. This form of communication continues into their adult lives.

How do cats purr?

What is most surprising is that cats have no special apparatus in their body to enable them to purr. Purring involves the rapid movement of the muscles of the larynx (voice box), combined with movement of the diaphragm (the muscle at the base of the chest cavity). The muscles move at around 20 to 30 times per second. 

As the cat breathes, air touches the vibrating muscles, producing a purr. Each cat’s purr is unique with some high pitched and others emitting a low rumble. Some purrs are so faint you have to be extremely close to your cat to hear it while others are extraordinarily loud.

The purr and meow combination

Cats have a special type of purr that they use when they want our attention, especially when they wish to be fed. This purr is known as a ‘solicitation purr’ and involves a combination of the purr and meow. Cat owners respond to this sound in a similar way that parent’s respond to the cry of their baby.

This is a wonderful example of how our domesticated feline friends have evolved to live with and be nurtured by us.

About Dr Joanne Righetti

Dr Joanne RighettiDr Jo Righetti is an animal behaviourist, educating people in all aspects of the human–animal relationship. Her background is in zoology, with a PhD in animal behaviour and a counselling diploma – qualifications which enable her to work with all sorts of animals – including the human variety! Joanne likes to help pet owners understand their pet's behaviour and solve any pet behaviour problems. She consults with vet clinics, organisations, companies,  councils, universities and media and is a regular guest on radio, with pet behaviour Q&As. Jo has also written a number of pet behaviour books and loves chatting to people on social media channels. Jo lives with a dog and 4 cats, as well as 3 sons and a husband. Find out more about Joanne at www.petproblemsolved.com.au.