I used to break chairs. I am way over the weight limit on the old ones at my high school. If there is a chair with a broken or missing book rack, all I have to do is drop down hard and the legs bend and the chair flattens. But that could actually get you in trouble.
Junior year in high school we actually made a teacher cry, funny as hell but sad at the same time. He quit that year too; got replaced by some old a-hole.
But if you have to ask things to do...that's kinda sad, just do random shit; teacher left class for a while once, we reversed the classroom. We even moved her desk and bookshelf, that was some heavy shit.
But then another part of me says grow up...but that part of me needs to mind it's own business.