Originally Posted by Tryst
What! That is dumbest thing I have ever heard. Stallions bite one another all the time when battling for mares. Not just nips - they draw blood and often, rip off ears, etc. The taste of "meat" is not going to curb disrespectful behavior.
Baby horses are like toddlers. They have to test everything to see what is allowed and what is not. You have to be the leader now and show him that biting is not allowed. Be it a loud No!! Or a good smack to move him away from you and make him reconsider this option. You must be 100% consistent that mouth on humans is not ever allowed! Neither is bumping you, leaning on you or pushing you around.
Where as I agree with you that it is a rather.. Unusual and bizarre thought... Try to remember this is a forum where people want to learn?!
OP, as has been mentioned, get a trainer pronto. You need to have someone help you read behavior of the horse.
In a natural environment, colts test. If they test another adult, or alpha mare they will very likely be chased away. If they don't heed that warning, they will be given a sharp bite.
My advice would be react and send him away with your body, and then act as nothing happened.
If he tries it again, and you don't feel happy with giving him a quick smack on the chops, grab skin on his neck and twist. As soon as you have done this, carry on as normal.
Is he in a field with other colts, or horses? If his behavior worsens it may be worth thinking about putting him in a field with a gelding (until he is gelded) that will teach him a few manners.