Originally Posted by olegreycowboy
Don't wait to correct the horse for nibbling, because you are too little too late. Correct him with an elbow or forearm for getting into your space. A pretty good bump to the nose, then forget it. It's over. No grudges. If he does it again a few seconds later, a firmer bump to the nose with the elbow or forearm. Then forget it. It's over. Be consistent, be fair, and be insistent. Think like the lead horse. Escalate if you need.