Many cat owners in Spokane have commented on how their cats click their teeth together when they see birds or other prey nearby. Some say they are simply mimicking the act of genuinely catching something. Cat owners tell of occurrences of their felines gnashing their teeth together when birds hover close to the window they are sitting in. The teeth-clicking sound cats make is sometimes coupled with quick twists of the neck to imitate breaking the bones of their prey.
Some felines make chattering noises that bear an amazing likeness to bird calls. This leads people to believe that cats could be trying to ensnare birds in as prey by impersonating the sounds of other birds to bring them closer. The cat will sit at a window and observe nearby birds, then make a series of short, amusing, chirping noises.
Another speculation as to why cats make hunting noises is to express their frustration at not being able to catch the prey they see. Most cat owners who claim that their cat makes hunting noises have indoor-only cats that survey squirrels and birds from inside, signifying that this behavior occurs only in cats that never go outside and get a crack at the tempting sights...
On the other hand, cats that make chattering noises when they watch birds outside may be indicating excitement to themselves or even their owner. Some felines wildly chatter and chirp when they see squirrels or birds near by and then run to other windows or to their owners, as if to warn them to the prey outside.