Your Cat's Tail Movements

Swishing...

A swishing tail (i.e. the whole tail slowly and gently moving from side to side) usually means Kitty is alert, curious and interested in his environment.

Lashing...

A lashing tail (the whole tail moving from side to side in a fast, aggressive way) means Kitty is agitated and annoyed. Sometimes when Kitty is doing this he'll adopt a generally aggressive stance. The hair on his tail may also stand on end, giving it a bushy appearance. If he's doing this, leave him alone or you're likely to become the victim of an attack.

Twitching...

If Kitty is twitching his tail at the tip, this usually indicates he's interested in something he's seen. However, it may also be the first sign of aggression - e.g. if another cat has just invaded his patch - and in this case it could turn to a lashing tail and aggression.

Quivering...

Cats will quiver their tails at the base as part of cat spraying behavior. However, they may also do this when they rub up against you, or when you stroke their backs, especially near their tail, when they're standing up. In this instance, the quivering is a sign of great affection for you.

Tail bolt upright...

With some cats, if their tail is upright (i.e. pointing towards the sky) when they're walking, it means they're happy and confident. The rest of their body language (e.g. the way they walk, the way they look around) will also reflect this.

Tail half tucked between legs ...

This usually means the cat is scared, unhappy or feeling threatened. The rest of his body language will confirm this (e.g. head down, ears back, body low to the ground.)


Meow....




Source:  cat-behavior-explained