To do teacher stuff you can, if you grate the soap the chalkboard while she is absent. Some time it will not be able to write on the Board.
You can create bad neighbors on the same floor in the Dorm this crap to close up the door lock or chewing gum to seal it with superglue. They will be long to open the affected door.
Put a chicken egg under the battery so that it could not be seen. After some time the egg will rot and will stink terribly, forcing the "victim" of our muck to find the cause of the stench. To make someone "fragrant" life you can also, if you soak the newspaper in a solution of nitrate of water (one to one), light it and extinguish. And the third option – Al2S3 stick in the flower pot. When flowers are watered, the smell will be, as from foul eggs. In order to prepare this composition, you need to mix aluminum dust with sulfur. First sold in DIY stores and the pharmacy.
If you are someone very much annoy, to get even with him quite extreme way. Light a powerful firecracker that has the capability to burn under the water, flush and run like hell, right away. The effect will be "explosive".
Without damage to the plumbing of the property you can do if a couple of packs of yeast to throw in the toilet and pouring sunflower oil. Then on the toilet is put a package of cellophane and the package is badly beaten with a pillow. Neighbors this prank is clearly "appreciate" when they want to relieve themselves.
And finally – are you in school/College or away, it doesn't matter. To annoy unloved teacher or negligent owner will not have no difficulty, if your pockets happen to have a raw egg and a syringe with a large needle. Will drive a raw egg with a syringe into the chair with a soft seat or in a chair. When the egg is rotten, the stench will be unimaginable. How do smells right and no one can figure it out.