PunksTank Yelling isn't something horses understand. If a horse turns butt and threatens to kick, your kicking puts you at risk of great harm. Some horses may startle, others may throw a kick so fast you can't get out of the way. In the field I'll take a rope and follow an aggressive horse. If he turns butt I'll start swinging the rope in circles, to worry him. He'll move away and I'll continue to follow. As long as he's moseying along, the rope is still. My goal is to get him to watch me with both eyes. When his eyes are on me his heels are the farthest away. I watch his ears as they tell me what is going thro his mind. I am ready to be proactive should it come to that. In a box stall, I'll remain outside and use a lunge whip to tap the horse's hip in a rhythmical fashion that gets annoying. The horse will begin to move. Even the smallest movement of his hip away from me is rewarded with the tapping stopping. I will wait a few seconds and start again. He'll start searching for the right answer which is both eyes on me and his butt the other way. I will leave him alone at this point (his reward). I will return in a while and assess the progress. He may need a refresher but it won't last long. When he's facing me this time I will offer a treat. I won't say that that is the end of it as somewhere down the road he may try it again, as that what horses do, test. A quick refresher and then it's done for.