Animalia, Arvicolinae, Chordata, Cricetidae, Mammalia, May, Muroidea, North America, Ondatra zibethicus, Rodentia, USA, Wisconsin, animal, environment, habitat, lake, mammal, muskrat, natural, nature, north american, north woods, northern, northwoods, pond, rat, river, rodent, spring, swim, swimming, water, wetland, wild, wildlife