For unwanted visitors: the cardboard guest bed

"If you do not have enough room for guests, a foldable bed is a smart choice. But traditional foldable bed is usually made from steel and so it is not easy to move. So, you need a cardboard one like this. It is made from 7 mm thick cardboard that is folded like an accordion. When you need a bed just unfold it and the room underneath the bed is pretty good for storage" ... and for making sure the unwanted guest has a bad night and doesn't ever visit you again.