Just got back in the fishtank game this year after a 13 year break... I have had 2 crayfish in my native West NC tank now for a while. One thing is these guys are smart and will try and find a way back to the river at first... so make sure you have some tape around the tank so they cant get out. Once they know that they have found a good home they seem to be very happy. Real easy to take care of. At night they like to hunt. If you have store fish... you might notice a fish is missing when you wake up. once I figured this out I just went back to the river and cought some minnows with a net. They are really smart and on high alert, seeming to be able to avoid the crawfish.
Best of luck,
Tron