Rusty Crayfish are native to the states of Ohio, Kentucky, Illinois, Indiana and Tennessee. They were most likely introduced to Wisconsin waters by anglers who used them as bait. It is illegal to possess both live crayfish and angling equipment at the same time on any inland Wisconsin water. It is also illegal to release a crayfish into a water of the state without a permit. They are very aggressive, displacing the native crayfish and destroying habitat.