Do they eat 'live' plants, or dead/rotting plants?

Also, since I was raising crays/shrimp in Montana, IF you live in Montana, don't advertise the fact that you have anything like crays, lobsters, shrimp - they are supposedly illegal - that said, the Fish and Game has no control over what is raised, kept inside a home or building according to the law, only what you might be raising outside in pools, cricks, lakes, etc.