Why do kittens like to bite people's hands?
1. The cat uses its paw as a toy
Owners often tease their cats with their fingers, and the cats will treat the owner's fingers as prey or toys, like a cat toy. Therefore, cats often bite their owners' fingers. If you don't want to be treated as prey by the cat, don't tease the cat with your hands.
2. Excessive
Sometimes your cat will rub against you, wanting to be petted, but prolonged or inappropriate pressure or method can make them impatient. If a cat bites your hand, it might be trying to tell you, "Why are you touching me so much? I can't take it anymore, I'm going to bite!" 
3. Comfortable expression
Cats are strange creatures. They bite you when they're happy, and they bite you when they're unhappy. When a cat is in a comfortable state, it will gently lick or nibble on its owner's hand if the owner touches it.
4. Feeling bored
Actually, sometimes cats get really bored. When they are bored, they will look around for something to play with. If they see their owner, they will walk up to them and gently nibble on their fingers. That's right, they just want their owner to play with them for a while.
