There is a crayfish for every type of standing water. Some need mud to burrow in and others need rocks to hide under. They occure accross the entire globe and no state or natrual body of water is with out them. Make sure you have something for them to hide under, someone mentioned bales of straw, and definetly keep them wet. Thier gills are inside thier shell so they can trap water in thier gills and live out of water for a while, but if they get to dry thats the end of them.
