Norway Rats: Size: 7-9 ½ inches long, Brown with scattered black hairs; gray to white underside.
Habitat and biology:  This rat lives principally in basements, on the ground floor, or in burrows under sidewalks or outbuildings. They appear to be most common about feed stores, chicken houses, and garbage dumps. Although more at home on the ground, these rats are adept at climbing and have been observed traveling along telephone wires from one building to another. They feed on a variety of items including both plant and animal materials, garbage, but their mainstay is plant material. 
Norway Rat