Lucky is playing with his new pack the same way he played with his puppy pack. Jersey used to do that all the time. Our trainer told us to cry out and "YELP" like a puppy would if it was hurt when Jersey would nip. That only made Jersey more playful. We would hold her snout and tell her no (a good firm "NO"!)and that helped some. Finally, we would just ignore her and stop playing when she would get like that. She learned that when she got too excited, we stopped playing with her and started controlling her biting. Another thing that helped was redirecting that behavior. When she would get like that we'd give her a toy to go and play with so that she learned not to play with us that way but that she could play with her toys that way. Eventually she learned to go get her toy first, then come to us when she was feeling frisky and playful.