House Mouse - Mus Domesticus
Appearance: Small and slender, three to four inches long, with large ears, small eyes and pointed nose; light brown or light gray; droppings are rod-shaped.
Habits: Nest within structures and burrow; establish a "territory" near food sources, generally 10 to 30 feet from nest; inquisitive, but very wary; excellent climbers.
Diet: Omnivorous, prefer cereal grains.
Reproduction: Prolific breeders at two months; can have litters as often as every 40 or 50 days, with four to seven young per litter; live up to one year.
Other Information: Feed 15 to 20 times per day; can squeeze through a hole one-fourth inch wide; carry many serious diseases.
Pack Rat - Neotoma spp.
Appearance: Medium-sized, bodies measure about 8 inches, with the tail slightly shorter than the head and body combined. Varies in color from cinnamon to brown, gray, yellowish gray, or creamy buff.
Habits: Pack rats get their name from their habit of taking small, bright or shiny objects and hoarding them in their nests. They will take beer can tabs, bottle caps, bits of foil, coins, and jewelry just to name a few items.
Diet: After establishing themselves within a building, pack rats will feed on foods within the building but will continue to forage for most of their food outdoors.
Other Information: Pack rats are distinguished from Norway or roof rats by having more hair on the ears than either of the other two rats.
Norway Rat - Rattus Norvegicus
Appearance: Brown, heavy-bodied, six to eight inches long; small eyes and ears, blunt nose; tail is shorter than head and body; fur is shaggy; droppings are capsule-shaped.
Habits: Nest in underground burrows, from which they enter buildings in search of food; tend to remain in hiding during the day.
Diet: Omnivorous, but prefer meats; cannot survive long without water.
Reproduction: Reaches sexual maturity in two months; can breed any month of the year; litter may number from eight to twelve; females can have four to seven litters per year; adults live as long as one year.
Other Information: Most common rat in U.S.; limited agility, but excellent swimmer; carrier of many serious diseases.
Vole - Microtus spp.
Appearance: Voles are larger than the house mouse with adults measuring up to 5 inches in head and body length. The tail, however, is shorter in relation to the body. Their color ranges from blackish-brown to grayish-brown. They have a blunt nose, small furry ears, and a scantily-haired tail.
Habits: Because they are poor climbers, voles are almost always associated with the lower levels of buildings. Outdoors, voles establish a well-defined system of runways that usually tunnel beneath vegetation.
Diet: The vole will eat a variety of foods, including leafy green plants, seeds, fruits, and nuts. It eats fungi of all kinds in late summer and autumn. During the winter, it eats seeds, leaves of small evergreen shrubs, buds, twigs, bark, and even bared roots of shrubs.
Reproduction: Females can raise as many as 25 young in three or four litters. Usually there are six young in a litter. There can be anywhere from 2 to 11 young in a litter.
Other Information: Widely spread across the country, voles primarily live outdoors, preferring dense grassy areas such as meadows or fields.