One naughty school story is about a boy who put a fake bug on the teacher's chair. When the teacher sat down, she screamed in fright. Everyone in the class burst into laughter.
There was a group of students who decided to switch all the classroom signs around. So the art room sign was on the science room and vice versa. It caused a lot of confusion among the teachers and students for a whole day. They finally found out it was a prank by those naughty students.
In my school, there was a naughty student who used to draw funny faces on the back of the textbooks in the library. One day, another student found one of those books and started laughing out loud. The librarian was very confused at first but then realized what had happened when she saw the drawings.