The Pack rat, which is also called Wood rat or Trade rat, is a rodent of one of several species in the genus Neotoma. Very often, people mean the Bushy-tailed woodrat (Neotoma cinerea). Packrats are common in the deserts and highlands of the western United States and northern Mexico. They are smaller than a usual (Old World) rat, and usually have long, sometimes bushy tails. They are also not related to the rat, other than also being a rodent.