I agree wholeheartedly with the earlier posts. Crate training...puppy in the crate when you can't keep an eye on him. Exercise, exercise exercise. Plenty of chewing toys that are rotated in and out so he doesn't get bored with them. Try keeping him on a cord inside the house that connects you to him when you are moving around and from room to room so you always know where he is at and what he is doing. Prevention is better than correction.