Play biting and mouthing are natural behaviors for puppies. Almost all pups nip at our hands, feet, or clothing. It’s normal puppy behavior, even though we don’t like it! Puppies need to be able to play-bite and mouth in order to learn how to play more gently.
Puppies learn how to play gently primarily from their mom and litter-mates. Puppies learn bite inhibition by biting and nipping at each other: if one pup bites another too hard, the bitten pup responds with a loud and startling yelp. If the biter does not play more gently, then the puppy who was bitten gets up and leaves. This reaction helps train the puppy that hard mouthing causes startling noises or ends the game; while soft bites mean the play continues.
Unfortunately, many puppies are taken from their mom and litter-mates too early, so people must teach bite inhibition to them. This can be done by mimicking the reactions that the puppy’s litter-mates would give for inappropriate biting. To train a soft mouth, pet your puppy and let the puppy mouth your hand. If the puppy bites hard, say “OUCH!” in a high-pitched voice. If the puppy shows signs of remorse (i.e. backing away or licking you), then continue petting. If the puppy continues to bite, walk away, giving the puppy a short time-out. Repeat until the puppy restrains its bite.