Why does my cat chirp and chatter at birds?

It's one of the strangest cat sounds: your cat sits at the window, eyes locked on a bird, jaw quivering, making rapid clicking, chattering or chirping noises. "Why does my cat chirp?" appears among the top why does my cat… searches on Google.

What chattering is

Chattering (or "chittering") is a fast quivering of the jaw, often with little clicks, squeaks or bleats, usually while staring at birds, squirrels or insects the cat can't reach. The tail may twitch, and the body is tense and focused.

Why cats do it

Nobody knows for certain, but there are a few theories:

• Excitement and frustration. The most widely accepted explanation: the cat's hunting instinct is fully switched on, but the prey is out of reach behind the glass. The chatter is a mix of arousal and frustration.
• Rehearsing the kill. The jaw movement looks a lot like the bite cats use on prey, so chattering may be a kind of "practice run".
• Imitating prey. Some people suggest cats mimic bird calls to lure prey closer. It's an intriguing idea, but not well proven in domestic cats.

Whatever the reason, chattering is normal and harmless.

Chirps and trills: the friendly version

Not every chirp is about birds. Many cats greet their people with a short, rising chirp or trill, a sound mother cats use to call their kittens. If your cat trills when you come home or when leading you to their food bowl, it's a friendly "hello, follow me".

Give your indoor hunter an outlet

Watching birds is great entertainment (many people call a window perch "cat TV"). But a cat who spends hours chattering with no chance to "catch" anything can build up frustration. Help them:

• Play every day with a wand toy that moves like a bird or mouse, and let them catch it at the end.
• Use puzzle feeders so they "hunt" for some of their food.
• Give a window perch with a view, but if your cat gets very frustrated, limit the time or add a curtain.
• Protect the birds: keep bird feeders out of pouncing range, and consider keeping cats in at dawn and dusk, when birds are most active.

When to check with a vet

Chattering itself is not a health issue. See your vet if your cat's jaw quivers or clicks without prey in sight, or with drooling, pawing at the mouth or difficulty eating. That can be a sign of dental pain or another problem.