The long-tailed weasel has a small head with long whiskers, a long body and neck and short legs. Its tail has a black tip. It has brown fur on the upper part of its body and white to yellow fur on its undersides. In the northern parts of its range, it turns white in the winter. Long-tailed weasels in the Southwest have a white mask. The long-tailed weasel can be found in most of the United States, except for parts of south east California and Nevada and most of Arizona. In Canada, it can be found in British Columbia, Manitoba, Alberta and Saskatchewan. It is also found in Mexico and South America. The long-tailed weasel lives in a wide-variety of habitats including woodlands, thickets, open areas and farmland. It usually lives near a water source.
The long-tailed weasel is a carnivore. It has a very high rate of metabolism and eats about 40% of its body weight every day! Most of its diet is made up of small mammals like mice, voles, rabbits, gophers and chipmunks. It will occasionally eat birds and insects. It crushes its prey's skull with its canines. It uses scent and sound to track its prey. Its long, thin body makes it easy for it to follow prey into burrows.