Church camp pranks? For girls to pull on guys?

This is my last year as a camper, and I'm looking for some fun, harmless pranks for me and my friends to pull on the guys. We got them REALLY good last year, and they never expected it. They also never retaliated, so we need to get them even better this year. We like to attack at night, and we also can't go in their cabin. I hope y'all can help me!