Understanding the Purring of Cats Cat tail signs: What your cat's tail tells you You asked and we picked one question to answer this week: "Why does my cat shake her tail like a rattlesnake?", We've got the answer below from behavior professional Kenzie Korpela, IAABC SBA, CFVA. What is she trying to tell me? Vibrating tail??? : r CATHELP 20 surprising cat facts you've never heard before