When a cat is petted, it arches its back and raises its tail because it enjoys being touched by its owner. If two acupoints on a cat's body are touched by its owner, the cat will feel very comfortable and will arch its back and raise its tail. Female cats arch their back and raise their tails because they are in heat. During their heat cycle, female cats will raise their buttocks when they are courting a mate.
If your cat unconsciously lifts its rear end while you're petting it, it means: you're petting it very well! That's what the cat is thinking. Massaging your cat is also a great way to strengthen the bond between you and your feline overlord!
