I think that you should just leave the crayfish alone, because something might endanger the crayfish. We should only feed or do other things to them or for them,if you know what you are doing is correct.
I would just let it stay in the wild, in it's own habitat. It's okay to look at it and admire it, but just let it live in it's own world, doing the stuff it normally does.
Hope this helps!!