The Chattering at the Window, Explained

That strange clicking noise your cat makes at birds is one of the oddest sounds in the animal kingdom.

You have heard it. The cat is at the window, rigid, tail flicking, and from its mouth comes a fast staccato chatter, somewhere between a chirp and a set of teeth clacking together. The bird on the feeder is unbothered. The cat is not.

The frustration theory

The oldest explanation is the simplest. The cat sees prey, cannot reach it, and the chatter is a release valve. Supporting this: cats almost never chatter at prey they can actually get to. It is a window sound, a glass-between-us sound.

The rehearsal theory

A second idea is that the jaw movement is a rehearsal of the killing bite, the quick chomp a cat uses on the neck of small prey. Watch the jaw closely and the movement is the same. The cat is practising.

The mimicry theory

The strangest and most interesting. In 2005 researchers in the Amazon recorded a wild margay, a small spotted cat, imitating the call of a baby tamarin monkey to lure adults closer. Some researchers think domestic cat chatter is a vestige of that, a half-forgotten attempt to sound like the bird.

Your cat may be trying, badly, to speak sparrow.

Should you worry

No. Chattering is normal and the cat enjoys the window more than it minds the glass. If the bird-watching gets intense, a feeder a little further from the house keeps everyone calmer. Or lean into it. A window perch and a feeder in view is the cheapest television a cat can have.