THE BITING/NIPPING PUPPY OR DOG
A puppy who is biting you or someone else in the family is doing so because it has not yet learned the rules of playing with humans. Perhaps your puppy has not accepted it's subordinate position in your family. It may appear to be acting aggressively BUT, in fact, it is not being an aggressive, dangerous dog. At this point, he is just an obnoxious pup who desperately needs to be trained. Trained from day one, not allowed to get away with it as a baby then suddenly it's humans want to stop the behavior when it gets older. The behavior has to be stopped as soon as it begins. Never allowed to become a bad habit. Yes, once a bad habit the puppy/dog can still be retrained but it is twice as hard and confuses the animal as to why it used to be able to get away with such behavior but suddenly is being corrected for it.
The first thing to realize is that a puppy of any age will put everything and anything into their mouth. NOTE: Young babies/children also do this. They will put anything into their mouths during a certain stage of their youth. It is one way for them to taste, sense, feel, learn.
Young puppies also express themselves with their mouth. It then escalates during teething time at age -four to six+ months, as they has an even greater need to mouth everything. There are ways to change this behavior. NOTE: Not only puppies and young adult dogs but ANY adult dog that is under mental stress (such as going to a new home or in a new situation in the existing home) may mouth a person. This is done because they are desperately seeking attention or are trying to become an accepted member of the Pack. Or because they are ill at ease and/or upset with what is happening their lives. Humans replace other canine pack members in the domesticated dog.
Please understand that your puppy/dog is NOT BAD if he is mouthing you quite vigorously. If you administer any kind of physical punishment when he bites too hard, he will eventually respond in kind. He will learn to defend himself whenever anyone raises a hand to him and MAY become a dangerous adult dog. NOTE: Reread the last couple of sentences because no truer words were ever spoken.
During teething time provide things for him to chew on. For example, soak old wash rags in water, ring them out, and put them in the freezer. Whenever he has a need to chew on you or the furniture, give him one of these wash rags to work over. Provide a box filled with chew toys such as nylon bones or hard rubber balls for any puppy/dog of any age. To keep their toys and chew bones exciting, only give them one or two at a time. Then put them away and give the dog a couple of different ones. This prevents them getting bored with their toys.
It is best not to play games where your hand is near his mouth. If you do, however, train him not to bite when you are playing. As soon as he begins to apply any pressure to your hand, shout the loud (Not Angry) just loud command "QUIT" as loudly as you can. Startled, he will release and, as soon as he does, say, "Good Dog!" Continue to do this until you see him noticeably inhibit his bite. He will learn that skin is tender and that he can only press down very lightly during play. Be sure each member of your family follows this same procedure. Never play with gloves on your hand. He may bit down harder without your knowing it, and the next time you play with bare hands, you may get hurt. If the puppy/dog is not learning to control his biting, then say the command word loudly twice, still not listening, then you must simply say it and walk away. Ignore the dog totally. As if you no longer even see him. This final step puts a stop to it very quickly as this Non Violent Punishment teaches them that play time is over if they do not listen. NOTE: The one word command "Quit" is now only for this behavior, nothing else so as to not confuse the dog. No sentences, only the one word which a dog can learn quickly where a jumble of words only confuses the dog. If already using the command word for other behavior problems, then choose a different one that will now be for this behavior only.
It is never a good idea to have Tug-A-War games using anything because he will have to bite down very hard to hold on which retards the previous bite inhibition learning. This advice pertains also to any kind of toy advertised for such silly games. The reason for this is that a small child may walk in one day dragging say a teddy bear, and your pup, seeing it may grab it for his own and inadvertently grab fingers as well. "Tug-A-War games teaches a dog to bite down and hold for all they are worth. DO NOT play Tug-A-War with any pup or dog.
If your puppy is biting and pulling at your jeans, shirt sleeves, hands, anywhere for attention or because he is excited, tell him in a loud, firm voice, "QUIT!" Whether during play time or because he wants attention or because he is overly excited, it does not matter. Follow this documents training for any mouthing.
It is not often that "Holding A Puppy or Dogs Mouth Closed" teaches them anything at all regardless of what training books, etc. may say. And physically hitting them with anything is counter productive. As is throwing them outside or into a kennel. Again does not work, classed as counter productive.