I know this might sound stupid but there are two different bites: a harmful bite or an affectionate bite. Your cat is probably giving you and affectionate bite. Mine does too.
As long as s/he doesn't have ears lowered, the biting is a sign of affection.
It's her way of telling you that she loves you. When I had my cats, they would do this often. They were my protectors.
Its grooming the lice from you.:)
They do this to other cats. He/she is grooming you. You are fully accepted! :)
Once in a while, they can be a bit painful.
he wants to clean his toung after he got done licking his ***