Your cat's tail can tell you about what's going on inside her head. Tails are good indicators of mood. Take a little time to observe your cat's behavior and you will start to get a feel of the tales the tail tells.
Position: high. When your cat holds her tail high in the air as she moves about her territory, she's expressing confidence and contentment. A tail that sticks straight up signals happiness and a willingness to be friendly. And watch the tip of an erect tail. A little twitch can mean a particularly happy moment.
Position: curved like a question mark. You might consider taking a break from your daily business to play with your cat if you notice a curve in her tail. This tail position often signals a playful mood and a cat that's ready to share some fun with you.
Position: low. Watch out. A tail positioned straight down can signal aggression. A lower tail is a very serious mood. However, be aware that certain breeds, such as Persians, tend to carry their tails low for no particular reason.
Position: tucked away. A tail curved beneath the body signals fear or submission. Something is making your cat nervous.
Position: puffed up. A tail resembling a pipe cleaner reflects a severely agitated and frightened cat trying to look bigger to ward off danger.
Position: whipping tail. A tail that slaps back and forth rapidly indicates both fear and aggression. Consider it a warning to stay away.
Position: swishing tail. A tail that sways slowly from side to side usually means your cat is focused on an object. You might see this tail position right before your cat pounces on a toy or a kibble of cat food thats tumbled outside the food bowl.
Position: wrapped around another cat. A tail wrapped around another cat is like you putting your arm around another person. It conveys friendship.