While crayfish are the most common crustacean in the United States, we don’t commonly see them on on the farm. This one was found by my son in the barely seeping fall headwaters of Carroll Creek. There is one fact that everyone should know about crayfish; they eat almost everything. Omnivores in the extreme, there’s nothing a crayfish won’t try: insects, tadpoles, algae, plants, dead animals, etc. They’ll feast on almost anything. In fact, one source states that 40% of their brain is devoted to their sense of smell – your brain only uses 1% – in order to help them find food.