Your Cat's Tail: What it Says About Mood Cat Behavior Associates Why Do Cats Vibrate Their Tails? Reading Your Cat's Body Language Kinship she always vibrates her tail at this exact spot very.. confused?? anyone else experienced this? It looks like they are vibrating. When a cat's tail shoots straight up and quivers or rattles at the tip, it is the highest form of excitement they can show. It's a Cat tail signs: What your cat's tail tells you Cat Tail Language: 10 Secret Messages Your Cat Is Sending You With Their Tail Chewy