Your cat obviously cannot speak people language, so you need to learn cat language to find out what your feline is saying. Tail movement is a reliable source of communication because it tells you the mood of the cat. Sometimes other clues, such as meowing, are combined with what the tail is saying. I have found with my own feline family, that all cats generally speak the same language.
When your cat walks toward you with her tail raised and occasionally waving back and forth, she is saying that she is open to interacting with you at the moment. When she raises her tail in this manner to other cats, she is telling them that she is respectfully acknowledging their presence and is willing to be their friend.
When you are talking to kitty and petting her, chances are that she will raise her tail to you and wave it back and forth quickly. She is communicating to you that she is happy and appreciative of the attention you are giving her.
A droopy tail is cat language that says kitty is just checking things out and currently everything is neutral. But when she begins to wave that droopy tail, she is reconsidering the neutrality, and is probably going to change her mind soon.
Watch out when your cat rapidly whips or snaps her droopy tail back and forth. She is agitated. You need to, if possible, remove the source of agitation immediately!
If kitty has an easy-going, protected life without things in her environment threatening her, you may not often see her with a big, puffy, bottle-brush tail. But when you do, this cat language is showing surprise, fear, and bravery, possibly all at the same time. Kitty has either been surprised or threatened. Instead of turning and running off, she is bravely confronting whatever has frightened her. So she raises the fur, not only on her tail, but on her back as well. Since this makes kitty look much bigger, she is definitely expecting the enemy to be the one to turn and run off, not her!
How a Cat is Enabled to Use Her Tail In Cat Language
A cat’s tail is included in the vertebral column and its bones, which are called caudal vertebrae. Usually a cat has 19 to 21 caudal vertebrae. This varies with the cat breed, as cats with longer tails (such as Siamese) have more caudal vertebrae and breeds with shorter tails (as in Persian) have less. Even Manx cats, which appear to not have any tail at all, usually still have a few caudal vertebrae.
The muscles surrounding the bones in a feline’s tail enable her to move it in expressing cat language. At the end of the cat’s back where the tail starts, the muscles are big. They get smaller the closer they get to the tip of the tail, which is why a cat’s tail is tapered.