It's not always easy to convince a new puppy not to bite the hand that feeds him, pets him, or plays with him. When puppies play with each other, they use their mouths, so they might also be inclined to bite or "mouth" your hand during play or when being petted. This is rarely aggressive behavior meant to do harm, but it is a difficult habit to break unless you encourage your puppy to try an acceptable alternative behavior. The goal is to redirect your puppy's energy onto acceptable chew toys, and to teach her to be gentle when a hand is in or near her mouth.
Redirect your puppy's penchant for nipping and biting by offering her more acceptable objects (such as chew toys) whenever you pet her. This technique can be especially effective when children want to pet her. As you or the child reaches out to scratch her behind the ears with one hand, offer the chew toy with the other. This will not only help your puppy learn that people and petting are wonderful, but will also keep her mouth busy while she's being petted. Alternate which hand does the petting and which one has the chew toy. You may need to start off by petting or scratching your puppy for short periods of time, since the longer she's petted, the more likely she is to get excited and start to nip.
You must also teach your puppy to be gentle with hands, and show her that nipping results in unpleasant consequences. Teach your puppy that nipping "turns off" any attention and social interaction with you. As soon as a nip occurs, look your puppy right in the eye and yell "OUCH" as though you've been mortally wounded. Then ignore her. Leave the room if you must, but ignore her until she's calm, and then try the chew toy and petting method again.
When your puppy jumps up on you, she wants attention. Even if you push her away, she is still getting attention (even if it is a response that you might consider negative).
When your puppy realizes that she gets no attention from you while she's jumping up, but does get attention when she sits, she'll stop jumping up. Remember, once you've taught her to come and sit quietly for attention, you must reward her behavior. Be careful not to ignore her when she comes and sits politely, waiting for your attention.
Attempts to tap, slap, or hit your puppy in the face for nipping or jumping up are almost guaranteed to backfire. Several things may happen, depending on your puppy's temperament and the severity of the correction:
Set boundaries when playing "tug-of-war" or wrestling games with your puppy. When trained properly, these types of games can teach your puppy bite restraint and the limitations of rough play.
It's important that all behaviors, acceptable and unacceptable, be managed consistently by all family members. And remember that any method you try will probably not be effective unless you work hard to teach your puppy an acceptable alternative behavior.
It's very difficult for children under eight or nine years old to practice the kind of behavior modification outlined here. Children's first reaction to being nipped or mouthed by a puppy is to push the puppy away with their hands and arms. This will be interpreted by the puppy as play and will probably cause the puppy to nip and mouth even more. Adults should closely monitor all interactions between their children and dogs.