Sorry Loveless, but you need to feed them crabs!
They just wont survive on scraps, they will get hungry, aggressive and stressed.
They love mixed algae/fish meal pellets like those for corydoras cats, bloodworms and some veggies and fruits.
The fiddlers are quite easily cared for in an aqua-terranium setup, a beach of sand or fine gravel is best, as they roam on land more than red claw crabs. They will sometimes sit on a high surface and wave the large claw (males) to signal to females and mark territory, but you can pretend they are waving at you B)
The same diet as above will suit them well, but remember, water quality must be very good for crabs, so dont let the water stagnate
Ken