Frustration Teleportation

Overview
Frustration teleportation is when something that has fallen or been dropped teleports. The larger the object, the more energy required for teleportation. Therefore, large objects (flying saucers, bricks, grizzly bears) hardly ever teleport, while smaller objects can zip away at a moment's notice. This is demonstrated by pencils, loose change, and anything else small and useful. Car keys may also have the unique ability to teleport at will. The goal of this Law (yes, Law, it is much more important than a Principle) of Nonsense is to aggravate you, so things will always end up in the most awkward places (e.g. glasses beneath your foot, pencils halfway across the room, bricks and bears six inches above your head).

UFO's
Aliens have for some purpose thought it wise to use this force as a "puff of smoke" to escape from human observation. If spotted by an Earthling, they would cut the engines and channel huge amounts of Nonsense Energy into their craft's hull. This was not very effective. The ships teleported to the most awkward places -- perhaps an Intergalactic No-Park Zone or the bottom of a lake -- sometimes even leaving crew members behind (they aren't actually part of the ship). This is where rat dogs came from.

Calculating
Several attempts have been made to create an equation for calculating how much energy it takes to teleport certain objects. This is as far as they've gotten:

f(x)=Σ

Yep. They haven't finished it yet. As you can see, the summation isn't even complete. They gave up after five minutes of calculation. Since it is a Law of Nonsense there is no accurate way of predicting it.