I know this is not popular opinion, but when ours bit, we popped their fanny and told them each time they hurt someone like that I would pop them. They often are trying to express themselves or just control the situation.
While it may seem like they are not controlling it, they are- they got a reaction from the person they bit!
Show him a more constructive way to express frustration, maybe saying "I don't like that." And then do something that expels energy like going for a walk, climbing the slide, swinging. Whatever you can do. When they are active they don't have time to think about biting.
Popping him on his diaperd bottom also sends him the message that it is not acceptable behavior. He needs to learn what is acceptable ASAP. In today's world biting is transferring germs and well....I would rather not my kid bite things where there are so many fatal germs floating around. ;-)