Our puppy likes to bite fingers. What can we do?
Just as babies explore their world with their hands and fingers, puppies use their mouths.
Additionally, teething hurts and they are looking to relieve the pressure. To relieve the pressure of teething, offer crushed ice or half-melted ice cubes (strong, solid cubes can break teeth). Just so they can have fun chewing, make many toys readily available.
When the pup gets too crazy and begins to chew on you, do what the mommy dog does, yelp. Say "Whoa!" and stop the game, at least for a little while. Eventually, the pup will learn that if it wants to play, it must play nicely. This is called "bite inhibition."
Be patient -- a pup doesn't learn this the first time. However, there's absolutely no reason for puppies to have any inkling that biting on people is acceptable. If you're certain the dog isn't getting the message, escalate the punishment. When the dog nips, again yelp like a mommy dog and snap at the dog's nose by flicking your finger. Stop playing with he dog. Don't hit the dog in the nose. The sole intent here is to get the distracted pup's attention -- not to give it a shiner.
If the dog still isn't getting the message, spray it with a plant mister filled with cool water, and simultaneously yelp when the dog bites. Then stop the game.
There is no need to roll the dog over or grab it by the scruff of the neck. This is clearly over-reacting.