The killer shrimp is officially banned in Michigan. The shrimp eats almost anything off the bottom of a river or lake, and it eats a lot. The killer shrimp is originally from the Black Sea in southeast Europe, but after canals were dug, it has entered European rivers. If killer shrimp boarded a ship travelling to the Great Lakes, they could destroy the invertebrate populations that native fish and other animals feed on. Read more about the killer shrimp ban here.
