The reasons why cats bite their own tails:
1. When cats feel bored, they will keep chasing and biting their own tails.
2. When a cat’s tail is injured and feels pain, it will keep biting its own tail.
3. When a cat has fleas at the base of its tail and feels itchy, it will want to keep licking or biting its tail.
4. Cats love to be clean. They usually remove dirt from their bodies by licking their fur, and they keep biting their tails, probably to clean their own fur.
5. When a cat is in a bad mood and is restless, it may bite its own tail. The owner can interact and play with it to transfer its transfer power.