WAGGING OF THE TAIL

Question
WHEN A CAT WAGS ITS TAIL, WHAT DOES THAT MEAN?  

Answer
Hi, Barbara.  When a cat thrashes his tail from side to side, it indicates he's irritated or aggressive.  It's a good sign you should leave him alone, because touching him at this time is likely to result in a swat, maybe even a bite.

A twitching tail, on the other hand, just indicates curiosity or indecision.

And a rigid, straight up, vibrating tail expresses extreme happiness or excitement.