My puppy bites my larger dog, help!?

Im aware that dogs generally play with their mouths. However, when my puppy [5 months old] wants my big dogs [2 years old] attention or anyone else's, or even wants to play, he bites her neck or ears, but very hard. I also know that he may be teething, but he has pretty much ped the phase of biting everyone and everything, its mostly just Roxy that he bites. Is there any way or anything i can do to help her from a biting puppy attack? Thanks