Chattering

You've heard your cat chattering its teeth quickly and loudly, especially when it's looking out a window and spotting a bird. Behavioristshypothesis that this is a result of your cat's frustration at not being able to go outdoors and hunt for prey. They could also be elated and a little agitated.

Others assert that your cat's peculiar jaw movement may be a natural habit that enables its muscles to get ready to kill prey. In any case, your cat's behavior is quite typical.