Why do cats purr?

Few things are as relaxing as a cat purring on your lap. That soft, vibrating sound makes us feel calm, but why do cats do it? And how do they make it?

A sound that vibrates

Purring is a continuous hum that can be heard both when breathing in and out. It is made by very fast vibrations of the muscles in the larynx, which open and close the entrance for the air.

Purring with happiness

The most common cause is well-being: cats purr when they are comfortable, being petted or resting peacefully. As kittens they already purr while nursing, letting their mother know they are fine.

Purring to calm down

However, they also purr when they are nervous, scared or in pain. Some scientists think purring helps them calm down.

Vibrations that might heal

Researchers have studied whether the vibrations of purring, between twenty-five and fifty cycles per second, could help bones and tissues recover. It is a hypothesis that is still being investigated.

Do all cats purr?

Domestic cats, bobcats and other small cats purr. The big ones, like lions or tigers, roar, but they do not purr in the same way.

How to understand your cat

Besides purring, cats communicate with meows, their tail and their ears. If it purrs and rubs against you, it usually wants affection. If it is tense and hiding, give it space.

A fun fact

A domestic cat can purr for hours. Some also “knead” with their paws while purring, a gesture that comes from when they were kittens pressing their mother belly to get milk.

Activity: a purring diary

If you have a cat nearby, write down when it purrs and what it is doing at that moment. You will see there are many different occasions.

Something to think about

If your cat purrs while you pet it, that is a sign of trust. If it stops or moves away, respect its choice: cats enjoy it most when they choose the moment themselves.