[debbiect]

Sparky has just started biting in what I think may be aggression. He will pick up or find something on the floor he's not supposed to have (such as a small toy from a child I babysit) and run with it. I have to chance him down to get it, and this morning when I caught him and was taking it out of his mouth he growled and snapped at my fingers, breaking the skin. I sharply told him no and lightly popped him in the mouth. I'm not sure if that was the right thing to do. Then I put him in his kennel. He's lying in it now looking at me all sad eyed. How's the best way to nip this in the bud right from the start, without doing damage to him?