They’ll talk smack, steal your signs, key your car, turn over your trash cans, or throw something at you, preferably from behind, but they aren’t much when it comes to a straight fight unless it’s five on one. Pepper spray makes a nice back-to-school gift. Just a thought.
Check the local laws first. There are some places (and I'd assume a lot of them are near progressive colleges) where self-defense in any premeditated form is a criminal act.