Mille Lacs National Wildlife Refuge hosts one of only five common tern breeding colonies in Minnesota. The common tern is currently listed as a state threatened species, a Minnesota Species in Greatest Conservation Need, and a U.S. Fish and Wildlife Service, Region 3 Conservation Priority Species. Lake Mille Lacs offers an abundance of minnows which common terns require to survive. Hennepin Island provides a remote and secure place to nest, free from predators such as fox or mink that eat eggs and nestlings.