They get shut into crates at night so I can sleep, because no matter what noise they make, I can know they aren't climbing into the walls, and don't end up startling awake at every little noise.

(They're on leashes when not in the crate right now so I can give them run around time without worrying about finding them in the wall again. They had, fortunately, not figured out climbing up the inside of the wall to get away, just stacked themselves. That was when the no outside the crate without leashes rule happened.)