It's a natural behavior that puppies bite. By the time they start teething, they naturally need things to chew on. furthermore, dogs usually prefer to use their mouths on to manipulate objects, and this behavior begins at an early age when young poots begin to explore their world.
If you have a puppy and don't know how to tell her to stop biting you properly. just watch this video from Zak George and he is going to show you how you can train your puppy to stop biting you using sample tips and tricks.