Crazy things you've seen your horse do?

I used to have a beautiful white Arabian gelding that was incredibly smart; and he had a delightful sense of humor as well. When he wanted to get my attention he would pull the halter off of Goldie (our other horse), and then he would carry it in his mouth down to the big metal farm gate near the driveway. Using his head, he would clank halter against the gate, and the metal fittings on the halter made a terrible racket.
When he saw me coming outside to see what all the racket was; his ears would perk up, and he would hang his head over the fence and swing the halter up and down so i was sure to see it. Plainly as if he could talk, he was telling me "LOOK ! ! I've got Goldie's halter." and he would be so proud of himself for his little joke.
He could also open the pasture gate and sometimes we would hear him and Goldie galloping down the driveway at night; and then of course, he had to pretend to be wild and not be caught until he was tired and ready to come back home.