Deter the mouthing and be firm, it will pay off, it just takes time. I've had a few staffy's before and my current boy was a real handful. He's 2 years old in Feb 2010. He's an angel now but he was real bitey up to 4, 5 months old. We were real firm with him and also had the advantage of an older dog at home and she's very well trained. She kept him in line as best she could and eventually our hard work payed off. We were concerned about the biting, he especially loved going for ears,which made it hard to give him a cuddle. The flip side is though he still has a fetish for ears but now he loves to show his affection for us by gently pulling on our earlobes and giving a little lick. They are such an affectionate breed.