For this reason you should always work with your pet when he is a puppy.
It is possible to train an adult dog if your pet is an adult when you get it or when it develops this habit.
A puppy will retain training and will have his personality molded throughout the training process.
There are also different types of biting, what should be the main concern is preventing the puppy from ever getting to the point of actually hurting anyone.
This is why training will teach the puppy not to play roughly or use his mouth in any fashion that could cause pain to a human.
You should keep plenty of toys available for your puppy to play with, and never play games with him that encourage biting.
Sometimes during play the puppy may get carried away and nip at you.
If this happens you should sound out a high pitched "Ouch" immediately startling the puppy and letting him know that he hurt you.
This sound is similar to the sound that dogs make when they yelp out in pain so he should recognize what has happened and understand.
Never ever hit your puppy.
Physical violence will only cause more problems that you will have to work through with your dog.
This can also cause your dog to become very aggressive and may make the biting worse in the long run.
Instead the best method of reprimand is scolding the dog in a firm but gentle voice and then simply ignoring the puppy for a period of two to three minutes.
If you use this technique repeatedly the puppy will get the idea that no one will continue to play with him if he bites them.
The whole family, children included needs to maintain the training with the puppy so that he doesn't resort backwards or feel that because the child is smaller he can get away with nipping at them.
The puppy should not be allowed to bite on fingers even if this seems like affection or such, because it could lead to serious aggression later on.
If the puppy continues to display this behavior but the bite is not that hard, there is a simple technique you can use to discourage him from biting.
Hold his lower jaw between your index finger and thumb loosely once he has your hand in his mouth, being careful not to hurt him, grip tight enough that your hand goes wherever his mouth goes.
You shouldn't have to do these more than ten seconds for your puppy to get the idea.
Test the results by putting your hand near the puppy's face, if this worked properly he should ignore your hand or simply licks it.
If you get one of these two results quickly tell him what a good boy he is and give him a treat if you would like.
If this doesn't work for you try putting a bitter tasting liquid on your hands or you can even use gloves for this.
Use this technique every time your dog tries to bite and the taste should cause him to stop.
The problem with using gloves is that it may cause an unhealthy fear of gloves in your dog.
Older dogs are more difficult to train and you may have to take completely different measures.
You may also have to invest in a few items to make it easier to train them.
However, the investments will be worth it in the end.
You may need to get a muzzle to teach adult dogs not to bite.
To prevent him from biting a visitor it is a good idea to have one on hand and have friends and family call before coming.