We just got a 1 year old miniature pony, mostly as a lawnmower for our yard, and he seems to be trying to assert his dominance. He hasn't actually bitten anyone, but he takes a mouthful of our clothes and holds it in his mouth. He also swings his head around and opens his mouth like he's going to bite you when you stop scratching his favourite itchy places, or if you run out of treats. So far I've been saying "no, no biting" and pushing his shoulder away so he faces away from me every time he swings around. If he keeps doing it, I push his shoulder and then his rump (not hard, just enough to get him moving away) to drive him away, and when he comes back without opening his mouth, I tell him he's a good boy and give him pats. The man we bought him from called him a "cheeky little bugger", and he was used as a lawnmower there, as well. He hadn't been halter broken - I'm working on that (putting pressure forwards, back, side, up and down until he steps in that direction, then letting it relax and giving him praise), but I'm hoping to get rid of this threatening dominance thing, if possible.. Does anyone have any tips?