A friend kept her weanlings in a paddock between her house and the main barn
for several reasons. She could keep an eye on them, and they had to
socialize with humans on the way to and from the barn.
There was a corn crib at the end of the paddock and a favorite "game" the
weanlings (many foal crops, not just one) devised was to "grab the corn
cob". The object was to gain possession, and some of the chases were
hilarious to watch. One day one of the colts stopped, watching the play. He
then went to the corn crib, picked up a fresh cob and ran to the group,
trying to entice the others to chase him. They started, but then, as a
unit, seemed to decide that the newcomer was not THE object of the game and
resumed the chase of the original corn cob and its possessor!
It is my observation that horses have a sense of humor, but not if the joke
is on them. One of my young horses was romping in his paddock after an ice
storm and skidded harmlessly on a patch of ice. It and I laughed. The colt
looked in my direction, apparently not having noticed me earlier. He then
returned (STOMPED would have been an accurate description) to the ice patch
and demolished it!
It is also my observation that, while we should not attribute HUMAN behavior
to animals, perhaps we are ALSO ANIMALS and share many of their emotions and
general behaviors. We HOPE that we are different, but there aren't many
animals that set out to destroy others of their kind en masse!