If you've noticed your cat making a strange chirping noise as he stares out the window at flies, people, or other cats, no need to worry. It's called cat chattering, and it's just his predatory instinct.


Cats have a whole repertoire of noises they make to indicate how they are feeling: purring to signal contentment, meowing to say hello, and caterwauling, hissing, or yowling to indicate fear or anger. They also have a sound they produce when they are interested in prey: chattering. It's a noise you've probably noticed coming from your furry friend while she sits at the window, laser-focused on squirrels hopping from branch to branch or a trio of birds chowing down at a bird feeder. But what's going through little Fluffy's mind as she chatters away? Here's everything you need to know.

cat chattering at the window
Credit: Praphatsara Thatanawong / EyeEm / Getty

When Do Cats Chatter? 

Cat chattering (also called chirping or twittering) nearly always happens when a cat is titillated by a visual stimulus such as a bird or rodent moving about. These are her hunting instincts kicking in. Sometimes, you might also notice physical changes in your cat as she chatters: Her eyes may widen, her pupils may dilate, and her ears may tilt forward. She's concentrating hard, and her body shows it. 

What Is Your Cat Saying When She Chatters? 

According to Marilyn Krieger, certified cat behavior consultant in San Francisco, although there are a couple of theories on what causes cats to chatter when they're hunting, it appears to be an instinctual response. 

"Chattering might be caused by neurotransmitters, such as dopamine, as well as the hormone cortisol/adrenaline that is released into the system," Krieger says. And while the thrill of the hunt may illicit chattering, there might be another reason your cat reacts in this way: "Frustration," Krieger says. "If a pane of glass separates a cat from its prey, the chattering at the window may also indicate pure frustration of not being able to readily reach the prey," she says. Some cats might chatter when simply playing. "I've seen cats chatter over a laser pointer," Krieger says. 

What if Your Cat Chatters at You?

If you are playing with your cat with toys that are imitations of prey, such as toy mice, your cat may chatter at you while you're holding the toy. It's usually nothing to worry about. Just be sure to keep an eye on your furry friend and back off playtime if he looks like he's about to pounce. While your domesticated pet knows and loves you, wild instincts can't be turned off when supposed prey (especially when it's dusted in catnip) is around.