Yes, mine do it every time they see a birdie outside. I call it chattering.

In one of my cat books it calls it teeth chattering and it says that it's not really a communication noise but it's often produced when a cat sees something it wants but can't get to, such as a fly high on the wall or a bird on the other side of the window. The cat may be voicing it's frustration. The cat may also emit small bleating/nickering type noises as its teeth chatter.