That was our version of a snowball fight when I was younger. Sometimes friends would bring ATCs out to the camp (we rode mx bikes) and after a lot of roosting each other we would end up just stacking mud on the rear fenders, riding towards each other and tossing hunks of mud as we passed. If you could knock someone off their ATC with the hunk of mud, you got bonus points. Mud jousting I guess. Good times.