4954 N. Shamrock Place, Tucson, AZ 85705

Pack Rat/Wood Rat

Neotoma spp.

Pack Rat/Wood Rat

Physical Features

Bodies are 6-7 inches and tails 5-6 inches long. They have large ears, large dark eyes, long furry hair on their body and tails sparsely covered with hair. Their fur is soft and colored brown to gray with the belly being lighter in color. They have long hind legs and short front legs.

Life Cycle

Live young
Breeding occurs primarily in the spring with 1-5 litters per year. Litters can have one to four young. A litter is born after a gestation period of 33 to 39 days. Pack rats live singly unless mating or rearing young.  They can be found in dens close to the ground 3-5 feet in height and diameter. Some species build nests in trees.


  • Diet: Feed on seeds, grasses, and other vegetation.
  • Activity: Nocturnal
  • Preferred Climate: Dry environments since they get moisture from the foods they eat
  • Defense: Speed, agile climbing, and some species will jump
  • Cautions: Nests can have fleas that carry diseases. Rats are also known to carry disease and should not be handled.
  • Home Invasion: Pack rats will enter homes in search of food through small exterior openings. They are attracted to shiny objects.

Helpful Hints

  • Seal openings into the home.
  • Inspect perimeter of the home for possible nest sites.
  • Recommend regular pest control service plan.

Interesting Facts

Poison ivy is not poisonous to all. Wood rats will feed on the leaves, stems, and seeds of this unpopular plant.


Hantavirus is a virus found in rodent urine, saliva and feces. It will infect lungs and can cause HPS (Hantavirus Pulmonary Syndrome). The first symptoms will begin about two weeks after exposure to mice and will include:

  • high fever
  • body aches
  • chills
  • trouble breathing
  • abdominal pain
  • lower back pain

A couple of days after these symptoms start, severe respiratory distress will begin and lungs will shut down. HPS is very serious but with advanced medical care, most people do survive the infection.