I didn't know that either until I came home from a weekend trip one time and found mine in the corner of the room. It was completely dry and even managed to collect a dust bunny. Who knows how long it was there but it sure looked dead, it didn't move when I picked it up or anything. I figured I should at least try throwing him in the fuge just to double check before I tossed it. Sure enough, as soon as that sucker hit the water he scrambled under a little piece of rumble. It ended up living for a long time after that. I have no idea how long it was there or how long they can live out of the water but I was impressed.