What does it mean when a cat holds its tail straight up?

When a cat walks toward you with its tail pointing straight up, often with a little hook or quiver at the very tip, you're getting one of the few cat signals that's almost always positive. Unlike a lot of feline body language, which is full of "it depends," the upright tail is a reliable friendly greeting.

Behaviorists trace it back to kittenhood. Kittens raise their tails to greet their mother, and adult cats carry the gesture forward into their social lives, using it to approach other cats and people they feel good about. It's a learned, sociable signal that's specific to domestic cats and isn't seen the same way in most of their wild relatives, which tells you how tied it is to cooperative, friendly living.

The misreadings usually come from confusing the tail-up with other tail shapes. A tail held high but bristled and puffed is fear or arousal, not a hello. A tail that's up but lashing hard side to side is agitation. The friendly version is relaxed, smoothly raised, often with that soft question-mark curve, and it comes with a loose, forward-leaning body.

There's no "problem" version of a true tail-up to worry about, so the response is simple: take the invitation. Lower yourself a little, offer a finger or a flat hand at nose height, and let your cat decide whether to rub against it. Reaching over the top of the head or grabbing can cut the greeting short, so let the cat make contact on its own terms.