Good advice so far. Distracting and the "ow" sound (which tellS them that it hurts and is distracting). He's so young. He will outgrow it. I don't know how young your kids are, but do be careful. Their little teeth are like razors. And a nip to a child could either cause the child to be afraid of his/her new puppy or could cause the child to innocently react physically harming the puppy. For puppies, toys are for playing with, not fingers. But they have to learn that.
But he WILL outgrow it as long as you keep working with him. Just today, I was playing with Coby (8 mos old) with my hands (something we've not done very much) and it dawned on me how perfect his bite pressure was on my hand.... enough to hold but not hurt. The only time I get hurt is when we both reach for a toy at the same time. OUCH!!!
