Why do cats fluff up their tails?
You can tell a great deal about your cat’s mood by looking at his tail, but contrary to what a lot of people think, a fluffed up tail does not always represent fear and aggression in a cat. When my cat is in an ultra lively mood, she will sometimes run madly around near me, as if she is trying to catch something. When I turn around to see what she is doing, I notice her stood still right next to me, her eyes all wide with her tail upright and fluffed up like a feather duster. I can, however tell by her body language that she is in the mood for play not fighting and it is usually the cue for me to bring out a piece of string, or find a nice strong branch in the garden for her to chase after. When a cat is in direct confrontation with another cat you may notice his tail fluffing up, as well as the fur all over his body. What he is in fact trying to do is make himself appear bigger and stronger than his opponent. He will probably be standing upright and looking dominant.