Red Devil Crabs (Geosesarma species) are mainly terrestrial, they only need a small water area if any. High humidity is important. They are not brackish. Their natural habitats are woods, near sources of running fresh water. Toss them some dead or alive crickets or whatever bugs you have lying around. They'll start recognizing you.
Try Googling Geosesarma, you'll get more hits with information you're looking for. HTH
