So I brought back some crayfish from MO that I'd like to use to start a breeding program with... so I set up a tank for them in the living room and everything, half-full with water. Yesterday I came in from the garden to the bedroom and find one in the middle of the floor. I almost hit the celieng because at first glance I thought it was a scorpion. Turns out houdini as he is now named, pulled himself out by climbing up the air hose, then took a walk about in the house. It was pretty funny.
The moral of the story is, if you're keeping crayfish, keep a tight lid on, and anything going into the tank, needs to be tightly sealed through the lid. Fortuneately they can survive for extremely long times out of water, so houdini's just fine.
By the way, these are the three species I have... I'm going to seperate each of the three species into their own tanks a bit later, but for now, I just have 2 tanks, so they are all mixed.
Orconectes (Procericambarus) longidigitus (Faxon, 1898)
Blue Legged crayfish

Orconectes (Procericambarus) medius (Faxon, 1884)
Saddlebacked crayfish

And my favorite, of which I have the most of:
Orconectes (Procericambarus) neglectus neglectus (Faxon, 1885)

This is what Houdini looks like by the way.