Cats.

The thing about cats is this; Whenever you get into a strange position that you'll have to move out of in a few minutes, your cat will be there. Or, if you don't have a cat but you're around someone else's cat, their cat will be there. You'll start to get a twinge in your leg or your back will start to ache, and just as you're about to move, you'll feel the fateful paws of your back...