How and why do cats purr?

[YoureBeingASillyBilly]

This is possibly a well known subject but i have never heard any reasons for it. What i am asking is what is the physical set up inside a cat that isnt inside humans/dogs/zebras that allows them to purr? Is it a valve in their throat or something? And also what is the reason for tje purr? Evoluntarily (sp?) speaking i mean. When cats first arrived on the earth was there some sort or evolutionary benefit to the cats that purred?

A quick Google says that they purr because their brains talk to their voice boxes in a different way to us/other animals and so they vibrate certain muscles which cause the purring noise. Any cat that doesn't roar, purrs (cool to think of a Puma somewhere, curled up warm and full bellied, having a purr!)

As to why - they're happy or trying to wheedle something out of you (in that excruciating 'fixed grin' way that small children and my family have perfected!)

and what an amazing sound that would be to hear a puma purring.

So the purr is like a 'im so cute you'll want to keep me alive' thing like small babies have? That makes sense. I guess the purr must be an appealing quality in kittens to mother cats so they wnat to keep them alive.

Can you tell im having a sofa day with the cat on my lap?

Cats can purr when they're scared or angry or upset as well, it doesn't just mean happy.

Really dip? I didnt know that!

cats generally purr to show they are happy but when in pain or unhappy purring is a reassuring self behaviour

It's thought cats have a bone in their throats which vibrates in response to certain emotions, so the purring gets louder when they breathe in and out.

They do it reflexively, unconsciously, like babies do smiling. Yes people can smile almost compulsively in response to pain or stress as well as happiness (I;ve had this).

I didn't know cats purr if they're unhappy but Issey makes an interesting point about it being reassuring to them...

And anyway, cats being cats are pretty contradictory so there are probably a million reasons why they do anything

Try this: give your cat a lap/stroke or whatever non food thing gets a purr response.

Then get the treat bag out. The purrs are different. First is more steady and quieter ime, a give me food purr is louder/irregular. One of my cats does little whimper noises when food is coming. I think she realises it gets a response as it's cute.

My cat does the 'i'm starving' wail as soon as she sees me near her food cupboard and tried to trip me over to get the food on the floor!

She does a very odd noise when she is watching birds from the window that i can only assume is her imagining chewing their flesh!

Yourebeingasillybilly the odd birdwatching noise, it a kind of high pitched chatter? Because my Stanley does that, sitting on the window while giving the birdies the old stinkeye.

Her jaw goes up and down very quickly and she makes a kind of clicky sound almost the sound she makes when licking water up but quicker.

Ah - the 'chitter'. They only do that when they can't get at the birds in my experience so it must be some sort of 'Look what I can see' signal. When they're actually hunting, they seem to be deadly quiet.

Yea cozie! Thats exactly it- chitter. And yes only when inside looking out at them. When she's outdoors she is very stealthy and quiet.

Mine does jaw clicks and chirping at me whenever I stop the laser pen/toy on a string, and about 10 seconds later will proceed to do something monumentally naughty until I resume giving him my undivided attention.