Our pet crayfish (refugee from 3rd grade class explorations) likes to climb. We were warned (by the Petco guy when I went in to buy him a tank). This morning there was an empty tank sitting on the floor. Doh! Where was crayfish? We all searched. I probably logged a good 1/2 hour peering under furniture with a flashlight. We were wondering if we'd have to wait until we smelled his decaying body before we located him. We were pretty sure he needed to be in the water. How long can they live outside water? No one knew. He had been really active last night so I sort of suspect he made his escape then. Daddy finally headed off to the office. "I found crayfish!" he shouted. Crayfish had made it down all the stairs and was at the bottom. We actually had to get some tweezers to pry his claw out of the carpet fibers - he wasn't interested in being recaptured. He seems to still be alive. You got to admire his fortitude. He fell a good 1' onto a wood floor. Scampered across the wood floor, headed down a long/high flight of carpeted stairs. I am curious enough that maybe some other day I'll put him down on the floor (or have A do it since I am not a big fan of picking him up) and watch him go. Maybe.