The Norway rat is the largest commensal rodent in the US.
Identification
- Usually gray in color
- Small ears
- Tail is short relative to the head and body
- Droppings are 3/4 inch and blunt on the ends
Environment
- Can exist in large numbers in and around residences, basements, stores, warehouses, docks, sewers, or dumpsters
- Burrow to make nests under buildings, beneath concrete slabs, around ponds, in and around garbage and other locations suitable for food, water, and shelter
- Nests may be lined with shredded paper, cloth or other fibrous materials
- Usually become active at about dusk to begin seeking water and food.
- Eats nearly any type of food but prefers a nutritionally balanced diet, consisting of cereal grain, meats, fish, nuts, and some fruits
Threats
- Likes to borrow and can form extensive galleries
- Have litters of 6 to 12 young that can eat solid food within 2 to 3 weeks
- Young become completely independent at about 4 weeks and reach reproductive maturity as early as 3 months
Treatment
- Traps placed indoors near entrance points and known runways
- Burrows outdoors may be baited
- Exterior bait stations may be placed on the perimeter of the structure


