After visiting my neice and nephew yesterday I thought I would post about puppies and nipping.  They have a 3 month old chihuahua/poodle mix that keeps "attacking" the kids.  I had to explain that puppies don't have hands and that their mouths are used to explore the new world that they are in.  Yes those sharp little teeth do hurt but here are some tips when dealing with a nippy puppy.

Teaching a puppy new commands is very difficult, they are more likely to respond to a sound rather than a slur of words.  The goal of training not to nip is to teach your puppy not to do something at all rather than to cease the behavior in response to a command.  If you have a puppy that nips try making a high pitched yelping noise, mimicking another pup in the litter would do when nibbled on.  This noise should startle your puppy from chewing on your ankle and at that point you can shove a chew toy into your puppy's mouth. 

For persistent nipping behavior you can try to hold the muzzle for a few seconds, the puppy will probably whine but don't worry he's not hurt.  You can also try a timeout,  essentially no more playtime or attention from you.  After a few minutes the puppy will calm down and you can play again.  The puppy should learn that doing a certain behavior means no attention from you, while not doing that behavior means a lot of play and fun, which is what most puppies and new owners seek.