Mitten crabs are an invasive species, not native to North America, originally from Asia. They are considered to be Omnivorous which means they are able to feed on different trophic levels. When the juveniles feed on algae, they are acting as primary consumers or herbivores. However, when more mature crabs eat worms, small crustaceans, fish carcasses or steal bait from fisherman, they are acting as secondary or even tertiary consumers. This implies that they can act as flesh eaters. They also feed upon detritus. Mitten crabs are scavengers and very opportunistic. Since they are not native to the United States, they compete with native species for food. Little is known about what will eat a mitten crab in this country. However, white sturgeon, striped bass, raccoons, bullfrogs, catfish and various wading birds have all been reported to feed on mitten crabs.