Name: Pack Rat

Scientific Name: White-throated Wood Rat: Neotoma Albigula; Stephens’ Wood Rat: Neotoma Stephensi; Mexican Wood Rat: Neotoma Mexicana

Description of Pack Rats: Packrats are gray to brown in coloration with a size of up to 13 inches in length.

Packrats such as the white-throated wood rat Neotoma albigula have a light-colored underbelly, white feet and a thickly-haired tail.

Packrats differ from roof rats in that they have shorter, thicker tails and a white underbelly. Packrats are by far the most attractive rats in the state of Arizona, if a rat could ever be considered elegant.

Pack Rats Range and Reproduction: The Packrats are widely distributed throughout the United States and Canada. In Arizona they occupy the Sonoran and upper Sonoran deserts and scrublands (N. albigula) in great abundance. Packrats (N. albigula and N. stephensi) are also found in the pinion juniper woodland and up into the ponderosa pine ecosystem (N.mexicana).

Breeding generally occurs in the spring. Woodrats produce 1 to 4 young per litter and may produce more than 1 litter per year in the southern, warmer climates.

Health Information: The elaborate nests of Packrats are breeding grounds for kissing bugs (aka cone-nosed beetle, Mexican bed bug, assassin bug) whose bite is painless but can make a person very sick. While some people can be bitten and not even know it, others will tell you that a kissing bug’s bite is worse than a scorpion’s.

Pack rats harbor fleas, which have been proven to carry bubonic plague; this has affected and killed several Arizona residents in recent years. Botulism and salmonella are spread via Packrat droppings. Arenavirus (Whitewater Arroyo virus), has also been detected in Arizona packrats.

Important Facts on Pack Rats:
•    Pack rats are some of Arizona’s most abundant native rats. Packrats are famous for their distinct nesting behavior where they construct nests or middens similar to a beaver lodge in construction but smaller in size.

•    Packrats are opportunists and will construct nests from sticks, rocks, cactus, pinecones, and other various debris.  Packrats use established nests for generations and under the right conditions these nests have been reported to grow to be thousands of pounds in weight.

•    In a residential setting, packrats will gather rotting trash, pet waste, children’s toys and landscaping trimmings. Packrats are curious animals and will collect shiny objects such as jewelry and eating utensils.

•    Packrats can destroy an attic’s insulation in only a few years with sticky tar-like urine, droppings and nests.

•    Wiring is a favorite target of the packrat due to a sweet linseed or cottonseed oil ingredient, and as a result of this, an infestation may pose the threat of fire.