Muskrats are a medium sized rodents ranging from 16 to 28 inches long. They have thick brown fur to keep them warm in cold water. Their tails are used to aid them when swimming, these mammals can hold their breath for over 12 minutes. Heavily relying on plants they will populate an area quickly. Though as the population grows the plant matter will decline causing their population to crash.
Top photo: Peter Pearsall/USFWS
Bottom photo: NPS/Jim Peaco