To stop biting, you must communicate to your puppy that you do not like that. When puppy bites gently, you may allow this since puppies need to learn about bite inhibition, what hurts and what does not. However, when it begins to hurt scream out "Ouch!", make firm eye contact and turn away and ignore the puppy. 15 seconds later, return your hand and see if he bites again. If so, repeat your response even louder. When your puppy finally licks your hand, praise him. Soon he will learn what makes you give attention and what results in a noise to avoid. This mimics what Mom did when her puppy was too rough.