The Norway rat is the largest member of the subfamily in Oregon. This heavy-bodied rat has a scantily haired, scaly tail shorter than the length of the head and body. The ears are membranous and lightly furred. The pelage is course, a grizzled brownish or rusty gray dorsally and dirty white to yellowish gray ventrally. Albino, melanistic, and spotted specimens are known to occur in free-living populations.

This rat is distributed throughout the world in association with humans and in Oregon is found in most of the counties west of the Cascade Range and from some counties along the Columbia River east of the Cascade Range. It is a native of China and Siberia.

The Norway rat nearly always resides near human activity. In urban areas, rats occupy houses, warehouses, stores, sewers, garbage dumps, and any other place that provides adequate shelter and a nearby source of food. In rural areas, they reside in houses, barns, sheds, poultry coops, stables, granaries, silos, greenhouses, haystacks, woodpiles, refuse piles and almost any other type of structure in which livestock feed or foodstuffs for human consumption are stored or are available nearby.

Photo by Brett Jordan, Flickr