How to Read Your Cat's Tail Language 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 Why Do Cats Vibrate Their Tail? This Is What They Might Be Signalling With It We Love Catz she always vibrates her tail at this exact spot very.. confused?? anyone else experienced this? Why Do Cats Vibrate Their Tails? Reading Your Cat's Body Language Kinship Cat tail signs: What your cat's tail tells you