I have this puppy that's coming into one of my training classes, and I had a chance to meet him beforehand. He's about 10 weeks old, and he is probably going to be medium-large sized. He was found behind a gas station alone when he was about 5 weeks old, or younger, so he no doubt missed quite a lot in his puppyhood. His owner has had him for about 3-4 weeks I think. Anyway, his problem was "Aggression," according to most people. Of course, I don't believe that any puppy is "Aggressive," and coming from his situation, I felt he probably needed regular puppy manners taught to him. After I met him, I kind of realized he was quite a bit different. He uses his mouth a bit differently, and he uses it hard. When you reach for him, he alligator snaps at you. You pick him up, he bites at you. You do anything at all, he bites you. In between bites, he shows his teeth, in a sort of grin. It seems that this is all play to him, I believe. But when he bites, he bites HARD. Almost aggressive-looking and feeling bites. I picked him up, and he was turning and trying to nip at me (Like normal puppies do,). He was feeling pretty confident, and showed no real adverse reactions. I put my hand in a spot he wasn't comfortable with (I believe it was on his shoulders, but I don't remember.) And he went berserk, trying to get me to let go, and attempting to bite me very, very hard. I see this sometimes with normal puppies that aren't very used to human contact, as well. Of course, I didn't let go of him until he settled down. I'm feeling that this puppy needs to learn serious bite inhibition before "No biting," but he bites so hard that it's simply unacceptable. His owner was tapping his nose as a repercussion for biting, and I obviously told her not do do that, and the simple "Squeak and ignore" technique for now. I expect and hope for the puppy to learn good manners, if his owner sticks to it-- I'm hoping that It doesn't continue to the point where I have to recommend a behaviorist. Since I didn't speak to her or see that much of his behavior, I don't know. Any good advice for this type of behavior, or anything I should watch out for or try with this little guy? I'm well used to normal bite inhibition and discouraging with puppies, and I wish I could better describe how his temperament is just different. But maybe someone's come across a situation like this before?