[gsatell]

We found a 3 week old dog on the street and took it in. It has obviously never learned bite inhibition. It socializes well with both people and dogs, but is biting us too much and too hard (sometimes breaking the skin).

What should we do?

[Swissmiss]

You do need to begin, immediately, to teach your puppy that nipping on human skin is not acceptable. Pups that play with other pups learn "bite inhibition" faster – unfortunately your pup has lost that opportunity with his liter. If you can get him into a puppy class and one that allow some free socialization time at the end would be ideal. Also, it helps to socialize your pup to the things you will want him to tolerate as an adult. Google on "puppy stages of development" and a lot of info will pop up for you. Go to Amazon and search "Sirius Puppy Training" (Ian Dunbar).

If your pup nips at you, do NOT discipline him by holding his muzzle or saying "No!"
Simply yelp (like another puppy - loudly if you must) and leave. He learns (just as he would from other dogs) that biting too hard makes the fun stop and the playmate go away. You will have to do this more than once (like a mom telling you to make your bed or clean your room LOL). If he tags along, biting at your pant leg, simply squeeze into the bathroom or closet and leave poor pup on the other side of the door. Part of your prevention regimen should be seeing that the pup gets sufficient exercise, too.
The best little kit in the world: "The Ultimate Puppy Toolkit" (www.premierpet.com)

[gsatell]

What about mouthing? I heard that the only way to teach him bite inhibition is to let him gently mouth your hand and then do what you said to do when it's too hard.