Knowledge Base

What is the difference between Rats and Mice?

  • NORWAY RAT (Rattus norvegicus)

Also known as the brown rat or sewer rat, this is the rat familiar to most people. It is a dark, brownish-black rodent up to 9.5 inches long (excluding the tail) and usually weighs less than one pound. Its 6-inch to 8-inch tail is dark above and pale below. The Norway rat has a blunt snout and relatively small ears. Its droppings are about ½-inch to ¾-inch long with blunt ends. Rats may deposit 35-45 droppings over a 24-hour period.

  • HOUSE MOUSE (Mus domesticus)

Usually weighing less than an ounce and growing up to 3.5 inches long (excluding tail), the house mouse is the most common rodent in urban and developed areas. Its coat is gray to brown, and the tail contains only a few hairs. Mice have pointed snouts and relatively large ears. House mouse droppings are slender, ¼-inch long and pointed. During a 24-hour period, a mouse deposits about 50-75 droppings.

Other differences exist between rats and mice. Norway rats require about an ounce of water each day – one reason why they are often found in sewers and along rivers and streams. House mice, however, can survive on the water they absorb from foods. Norway rats prefer to live in underground burrows, but will live above ground in walls, ceilings and storage areas. Outdoors, mice will nest in burrows but will move into structures to nest in attics, wall voids, cabinets, appliances and furniture.

Updated 3/26/2013 11:16 AM
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