Why do Rodents chatter their teeth?

Question

I have a guineapig, sometimes he chatters his teeth.....

Answer 1

In guinea pigs, teeth chattering is an upset trait. its aggression or anger, and is usually followed by a nip or a fight unless the offending action is stopped. Don't confuse teeth chattering for the milder "chompchompchomp" of your guinea pig simply sharpening its teeth (much like us gnashing ours). Teeth chattering is loud, and shows that your piggy is pretty ticked off. Once chattering of teeth has commenced, a bite is almost certain to follow. Guinea pigs housed together that exhibit this behavior need to be closely monitored, even separated.

Answer 2

I don't have a guinea pig but I know that the teeth of the rodents keep growing for their whole lives so maybe that has also something to do with the teeth chattering...

Answer 3

my guinea pig does to. it depends..
if they lower themselves when they chatter they are mad or scared, or may start a fight
if u r petting them and they shiver and chatter they are happy, and content.
go here:

http://www.cavyspirit.com/sociallife.htm

and here:

http://jackiesguineapiggies.com/guineapigsounds.html