A Guide to What Your Cat is Communicating: A cat's tail is far more than just a balance toolit is a sophisticated emotional barometer that broadcasts their internal world. When your feline What is she trying to tell me? Vibrating tail??? : r CATHELP Quivering, Wagging, Puffed Up: What is Your Cat's Tail Trying to Tell You? A cat's tail is a powerful form of communication that reveals its emotions and intentions. When the tail is erect and twitching, the cat is usually excited or happy, while a straight up she always vibrates her tail at this exact spot very.. confused?? anyone else experienced this? Cat tail language Petplan