Ondatra zibethicus, muskrat

The muskrat occupies a niche along the soft-sided banks of ponds and wide streams where emergent aquatic vegetation is abundant. It feeds primarily on aquatic vegetation; preferring the succulent tubers and roots of the Nuphar sp.(lilies), Typha sp. (cattail), and Potomogeton sp. (pond weeds). It will also feed on crayfish, mollusks, small fish, tadpoles, and frogs. It competes with mink for the resources of shelter and food. They build elaborate networks of tunnels for protection against predation. Some areas are designated for feeding, others serve the purpose of escape and dwelling. The efficient use of available resources by the muskrat in wetlands often excludes other genera of the same family from successful competition in the same habitat.