What do u think about this high school prank..can i get arrested?

well my friends and i have planned on smearing the windshields of our principles and homeroom teachers with sperm. there's a total of 16 of us and we have started collecting our juice already. we collect & combine the sperm every week, then add it to a container in which its then stored in a cooler full of ice. We're still not sure if we should act out our prank in a cold day or during late spring, when it'll be warm and sticky. any suggestions?? also, there's like 4,000 students in our school, so can they test us to find out who it was that did this?