A puppy likes biting and chewing on almost anything that enters her world. Just as with jumping, biting between littermates is their style of play. Biting also teaches them how to use their main hunting tool, their mouth with all those teeth. Unfortunately, this often carries over into their interactions with the members of their new home. All the people, including the children, are brought into the game. Puppies have very sharp teeth, and a bite or nip can hurt and be terrifying to small children. There are several methods that are used to eliminate this behavior.
Startle response and redirection
Patricia McConnell, Ph.D., an animal behaviorist and adjunct professor at the University of Wisconsin, suggests a method which startles the biting puppy. Just as the puppy bites down, make a sudden, abrupt, high-pitched and loud 'AWRP' sound. This would be the same sound that a littermate would make if bitten by the puppy. The sound should be so sudden and sharp that the puppy is immediately startled and stops the behavior. If done correctly, you will be surprised at how instantly the pup removes his mouth and looks bewildered. At that point, quickly substitute a toy, such as a ball, the puppy can chew on. This redirects the puppy's biting behavior to the ball. This way the puppy learns it is no fun at all biting you, but chewing on the toy is. You may need to do this multiple times if the puppy gets excited in play. If the 'AWRPs' make the puppy more excited, try another approach.
Stop the action
Dr. McConnell also suggests that, in some cases, just immediately (and dramatically) leave the room when the puppy bites. This is certainly a method children can use. After multiple times, the puppy will learn that every time she bites she loses her playmate, and that is no fun at all.
Important prevention measures!
No matter what method you use, do not entice the puppy to bite you. Games like tug-of-war and waving your hands in front of the puppy instead of using toys may encourage the puppy to bite.