While you might think it's cute when your new puppy nips at your fingers in play, once she's grown into a 100-pound adult it won't seem so harmless. Teaching puppies not to bite at an early age will make things much easier for you in the long run and can avoid future behavior issues.
The Importance of Curbing Biting
Puppies are curious little critters and biting is their way of exploring the world around them. While it's usually harmless enough and well-intentioned, allowing it to continue can lead to aggressive or destructive behavior. If an adult dog bites too hard, even if she only means to play, she could seriously injure someone. It's vital to redirect her attention and teach her that biting people isn't fun or exciting.
Learning Bite Inhibition
Bite inhibition is when a dog can control how hard she mouths. A dog who learns bite inhibition is less likely to hurt someone or break the skin should she ever bite, due to fear or pain. A puppy should learn this when playing with her siblings, which is one of the reasons it's important a puppy isn't taken from her litter too early. When a puppy bites her sibling too hard during play, the other will yelp and stop playing for a time. To avoid play being interrupted, the puppy will learn to use her mouth more softly.
How to Stop Biting
You can use the principles of bite inhibition to teach your pup not to bite. Each time she nips you, make a yelping sound or loudly say "ouch," then fold your arms and completely ignore her for 10 or 20 seconds. She will soon learn that biting doesn't get her any attention -- in fact, quite the opposite. You can also try redirecting her, by giving her chew toys to play with or by feeding her treats while you're stroking her, so she won't start nipping at you.
What Not to Do
Never punish your puppy for biting by hitting, tapping or any other means. This may encourage her to play even more roughly and could make her afraid of you, eventually leading to more aggressive behavior. Don't play any excessively rough games with your puppy -- such as wrestling or letting her grab at your clothes -- but don't stop playing with her altogether, as it's an important way to bond. Avoid waving fingers or toes at your pup to get her in a playful mood, as she'll be enticed to lunge at them and nip.