When 64 high school students in Michigan decided that their senior prank would be to stage a bicycle parade en route to their school, none of them — including the town’s mayor, who participated — expected that the school’s principle would threaten to bar them from graduating.

But that’s precisely what happened this week at Kenowa Hills High School in Grand Rapids, Michigan.

Instead of committing the traditional senior pranks, the Kenowa seniors instead decided upon an activity that promotes good health and a cleaner environment.