What's His Tail Telling You?
Understand how to read your cat’s body language.
Cats can use vocalizations—like meows and purrs—to let us know what they want, like or dislike. But a large part of their communication is based on body language—much of it conducted through their tails.
The primary purpose of your cat’s tail is balance—it helps when walking out on a limb, and more importantly, it helps him flip in the air to land on his feet should he fall off that limb. But our domesticated cats use their tails to communicate with people and other cats, sending messages with their tail based on its position and shape.
The position we're most familiar with is the straight up "greeting." The tail is vertical like a pencil, and you usually see it when your cat is happy to see you. If the tip of your cat’s tail is bent slightly, it generally means he's very happy.
A tail straight up with the fur bristled out communicates the opposite meaning: Your cat feels threatened. Usually when your cat is in this mode, he'll stand sideways to the perpetrator, back arched, in order to appear as large as possible.
A cat often uses his tail to communicate intentions in order to avoid conflict. A cat being petted will communicate that he no longer likes it with a slow swish of the tail—it’s a first warning. If the unwanted petting continues, your cat may bat at you with a front paw or get up and walk away.
When your cat is particularly agitated he will whip his tail rapidly and may accompany that with a low growl. When stalking prey—real or toy—your cat’s tail will be straight out, twitching or quivering. This is usually seen when the cat's whole body is spring-loaded, in pre-pounce position. This subtle movement of the tail communicates his intentions to other cats without alerting their prey.