Keeping Myself Entertained

It's really winter here and there's not much to do. It's cold and the ground is covered with ice and snow. It's not usually like that around here. It's been keeping me in more than I'm used to and more than I can take. So I'm finding new ways of entaining myself. Mostly by pulling pranks at work.
One of the other teachers here who works on the third floor like me has two doors that go into her room. One main enterance and one back door that is connected to a small supply room and another door leading to yet another classroom. I use that small room to cook stuff in the microwave that is in there. Always there is all kinds of stuff laying around- mostly stuff for projects and supplies for experiments. So everytime I go in the small room to use the microwave I take the two or three minutes it takes to heat my food or water to place something against the door that will fall on the first person who comes through the door of the other classroom. The first time I leaned two brooms against the door and never heard what happend. Then I started leaning other stuff against the door. I never heard anything about the result. No one complained. So I started placing items on the handle of the door opposite the side of the classroom- plastic jars that would make a bunch of noise, books, whatever I could find in there. Still no response. Yesterday, I placed this huge beachball thing hanging on a string right in front of the door so when the door opened it would swing in and attack the person opening the door. Finally this moring