pack rat, rodent of the genus Neotoma, of North and Central America, noted for its habit of collecting bright, shiny objects and leaving other objects, such as nuts or pebbles, in their place; also called trade rat or wood rat. Most common in the southern and western parts of the United States, but found as far south as Nicaragua, the pack rat stores the objects it collects to decorate its nest. The rodent may reach a length of 18 in. (45.7 cm) including tail, has soft brown fur, and resembles a squirrel with large ears. It eats nuts, berries, seeds, twigs, and roots. Its nest is a large stick structure built in a sheltered area. The desert species adorns its nest with bits of cactus, turning it into an impenetrable fortress. A litter is born after a gestation period of 33 to 39 days and contains from two to six young. Pack rats are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Rodentia, family Cricetidae.
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