Why does my cat shake her tail like this? Anyone else's cat do this? She vibrates her tail when she is happy to see me Why Do Cats Vibrate Their Tails? Reading Your Cat's Body Language Kinship What does this tail shake say? : r cats Rattlesnake Tail is one of the signs of the *most* excited happy cats. It can be confused with the behavior of spraying, but in a fixed cat, its actually just an extremely excited cat!!!!! #happycat