What methods have you been using so far in teaching Cody bite inhibition? Biting and using their mouths is absolutely normal dog behaviour - and dogs need to be taught what is and isn't appropriate. They learn this from each other, and in a human household, they need to learn from you
With puppies, what generally works the best is mimicking the reactions they would get from other dogs or their littermates. When the dog bites or puts it's mouth on you (beyond what you decide is appropriate) then you should YELP loudly in pain, and withdraw from / ignore the dog for a few minutes. That way he gets the idea of how much pressure he can exert with his mouth in 'fun' and where he has to draw the line.
Do a search here on 'biting' and you'll find plenty of previous threads and good advice given to others in similar situations. Good luck
