What to do with tampons for some fun in class?

its the end of the year and i just wanna have some fun. what can i do to freak my teacher out with some tampons in class? like where to put them? and should i keep them wrapped or unwrapped? i mean obviously, i would never put a used one, that's gross and unhealthy. but, i just wanna have some fun. ...or any other ideas for some other funny things to put around class?