12 Scientific Explanations For The Weird Things Cats Do
7. Why Do They Purr?
Surely the ultimate sign that your cat is happy and contented is a strong, lawnmower-like purr and drooping eyelids, but why do cats purr?
It is thought that purring begins as a way for kittens to signal to their mother that all is well, whilst simultaneously nursing. Seeing as a kitten cannot meow and drink milk at the same time, the reassuring rumble is a way of putting mum's mind at ease.
Purring is actually a reflex, they simply can't help themselves, which is why they purr when you stroke them. It is an instinctive response to tactile social behaviour similar to nursing.
Cats don't just purr when they're happy though. Sick or injured cats will often purr as a way of reassuring themselves, perhaps reducing their stress by reminding themselves of a time when they were safe and warm with their mother.
This can present quite a problem for vets as it is very difficult to listen to a cat's heartbeat or breathing when they're purring their head off.
Weirdly, cats will not purr when they can hear running water, so vets will often run a tap if they need to examine a cat that can't stop purring.