Horses also kick to defend themselves, and these kicks are often powerful and well aimed. Horses may defend themselves by kicking when they feel another horse is getting too close to its food, its foal, a special herd mate or if another horse is acting aggressively towards it.
Is it OK to kick a horse?
Those people in our barn who have Western discipline upbringing say it's okay to kick the horse in the ribs (much like you would thump on one if you were riding and the horse wouldn't respond to leg aids), and the English group says no kicking from the ground, but kicking while riding is okay.
Why does my horse want to kick me?
Horses are generally scared animals and they like to have strong leaders that act predictably. ... If your horse doesn't feel safe with you, then he stops respecting you. Then, if he starts feeling like you got in his way, he might kick you or bite you despite you want the best for him.