It's normal and even cute when your puppy nibbles and even lunges at your hand. Since your puppy has been exposed to only other puppies in the litter who naturally play with mouthing and biting, it would make perfect sense why he would assume that playing with you wouldn't be different. But as they grow and their bodies become stronger, what was once cute nibbling eventually turns into uncomfortable or even dangerous rough playing bites. go here for more
Carry a handful of treats (or one of these convenient treat pouches). Walk around your yard, giving a treat to your dog while you’re walking every few steps. Give the treat down at your side, by your thigh. The idea is to convey ‘being right here next to mama when she’s walking means I get treats!’ Otherwise, completely ignore your dog. If he moves off and reaches the end of the leash, just stop walking until you get enough slack in the line to keep moving. How Does Cesar Millan Train A Dog With A Leash ?