LOL! I love this - I thought my horse was weird but he's not alone - hahaha! My yellow horse loves to lick everything. He is as bad as cat grooming himself. He licks me, licks the other horses, licks the fence - I know he isn't mineral deficient or anything else, because I've run blood tests on him myself. I think it is just his personality and I don't ever scold him for it. I know that he does it to play for the most part, because he tends to do it more when he's playing with his jolly ball with me or another horse.
I think it is cute, but it puts everyone else on edge because when he licks someone else, I know they are hearing the tootsie roll commercial play in their head - how many licks before you get to the center of a tootsie roll tootsie pop? 1, 2, 3, CHOMP... but he never chomps...LOL!