Okay everyone. Start with a giant pile of boxes. Fit them all into one big box so there aren't any excess spaces. Helps if you have great Tetris skills--I used to be able to beat the gameboy. Take your trusty box cutter and cut from outside to inside box. Next cut from inside box to inside box for the maze effect. Then I added a layer of cardfboard and then the second level of boxes and cut a hole at each end up into the second level and cut pathways on the top floor just like I did on the bottom. Fold top closed and tape it down and your all set for hours of fun, chewing and digging.