CHICAGO — Well, it’s that time of year again. Time to stash a dead fish somewhere to stink up the school hallways. Time to drop tennis balls on the heads of people in the lobby. Time to cover your soon-to-be alma mater with Post-It notes.

For high school seniors, it’s prank time – or “structured mayhem” in the words of Mindy Utay, a therapist who works with teens.

It’s a rite of passage as graduation looms, mostly harmless fun but sometimes a escalating into vandalism. This spring alone, windows at school have been smashed, walls and sidewalks spray painted, and paint poured down steps. Cars have been flipped. Property has been damaged from California to Kentucky to Maryland.

As a result, school administrators are rethinking exactly what constitutes a prank and where to draw the line – and finding that’s not always easy to do.

This year, the rule at Kenowa Hills High School in Walker, Mich., was clear: No senior pranks allowed.

But organizing themselves on Facebook, a group of graduating seniors there decided to ride bicycles, en masse, on the last day of school. They arranged for a police escort along the 3-mile route. The mayor even brought them doughnuts before they headed out to what was supposed to be a funny surprise for everyone else at school.

The principal was not amused.

She thought the students had put themselves in danger by riding along a busy thoroughfare. Traffic was disrupted. Drivers caught up in it, including some teachers, were late for work. In the principal’s mind, the seniors had broken the “no pranks” rule, and she came down hard.

“But we didn’t really see it as a prank. We saw it more as a senior send-off,” says Sarah Pechumer, one of the 65 graduating students who participated. “It was harmless. It was arranged. It was legal.”
By MARTHA IRVINE 06/06/12 07:54 PM ET