Why does my cat chatter when he sees a bird ?

[Dougie69]

Why does my cat "chatter" his jaws together whenever he sees a bird, especially when in the house sitting on the window sill looking out, or in the middle of the lawn ?

[panchyboy]

that remains a mystery to me to. my cat tends to just open his mouth and forget to close it.

[Morrisonker]

i always wondered if the cat is trying to entice the bird towards it.  My mum's cat does it from the bedroom window on the 2nd flor and you'd be surprised the amount of birds that end up in the house.

[irisred]

According to a cat pschology book - they are envisaging eating the bird - its a bone crunching thing apparently.  Nice huh?!

Can never say I've seen my cat eat like that tho and would be slightly disturbed if she did...

[Piper-AK]

Cat's actually have a type of sensor at the back of their throats for smell molecules that is far more sensitive than noses (or tongues).  When they do that weird 'chattering' thing with their jaws, they are actually sort of tasting the air to get the flavour of a really dilute smell.  Our cats used to 'chatter' when they were underneath a window ledge and could not possibly see the garden, with their jaws pointing to where the bird was, and we would stand up to look out of the window and sure enough - there would be a bird on the lawn exactly where they cat was 'looking'.  It really freaked me out until I found out why.

[mycatis]

One of my cats used to do this a lot, I think it's pretty funny and cute

[drgnrdr]

Now these are some interesting answers...

 I was told long ago that the cats use to try and imitate the birds chittering and such, they would get closer to the cat. I tried it on a few cats and one cat I had really was a bird fanatic, I chittered and he came running, if there was no bird outside the window he would look at me and go off, wondering what I was doing if a bird wasn't there, and maybe cussing at me for getting him up for no reason...LOL

[Bottom]

My cat does it when the reflection from the sun shines off of a watch or mirror on to the wall creating a little moving light patch, Its really funny to watch.

[shnamo]

This is probably a totally useless piece of information but the weather is rubbish and iI have nothing better to do with my time. Anyhoo, I used to have two guinea pigs who didn't get along. When ever were near each other, they chattered their teeth and if we put them together at that time, they'd fight. I've since found out that it's a sign of agression with guinea pigs. Maybe it's the same with cats?