If you have a foal, you can almost always keep them from biting or kicking as a habit.
It's how you train a horse for manners.
Like kids, horses need it.
It is at this young age that we must take opportunity to teach them what they can and cannot do.
Thus, we must learn to train a foal if we are to train a horse.
A foal is very quick.
One foal will play with another where they will nip at each other and run away before you can set him straight.
Thus, you have to plan ahead and be watching out for it.
It's a BIG No-No to let him kick or nip at you and run off.
If that happens, he'll think he's in control and can do what he wants.
It won't happen.
If he wants to nuzzle you, never let him do it on your body...
just your hand.
If he takes a nip at your hand, you can flip your finger at his nose, or poke him.
This will teach him real fast that he doesn't want to nip at you.
Be careful not to overdo this.
Only use what is necessary because you don't want to make him head shy.
Rather, just get him learning he can't nip you - ever.
Always try to anticipate if the foal is going to get a little naughty.
If he does, be ready.
Act quickly.
Some foals grow through stages of nippiness, hard to catch, or being uncooperative.
It's simply a test to see if you are "really" the boss.
The trick is to handle them kindly but as firmly as necessary.
(Kind of like a handling a kid).
Done right, and the horse will usually not end up rebellious and he'll have pretty good manners.