so i got my puppy sunday and he really is lovely and so sweet and cuddly, and i love him to bits. he's catching onto potty training really quickly and walking on a leash.... less quickly, but i'm having one really big problem with him. when he wants to play, he bites, a lot, and really hard. it hurts, leaves marks, and i'm surprised he hasn't broken skin yet. i always try to replace my fingers/ears/nose with a toy and he'll play with it for like 30 seconds, but then he's back to biting me! i know he isn't trying to be aggressive and is just playing, but how do i stop it? i have nieces i want him to be able to play with, and it just hurts!