You could probably give him worms,grubs,sometimes they eat fish food also.the encyclopedia says little fish,minnows,or snails ,but I fed them that other stuff and it was fine and easier to find!
What Do I Feed A Crayfish?
That is because everyone needs to eat. If you eat they do.
You can probably feed him crawfish/crayfish bait.we have aa crawfish/crayfish pond and my dad feeds them either bait or cut up fish