The Norway rat, also known as the brown rat and sewer rat, are robust rodents with coarse brownish and scattered black hairs, gray to yellowish-white under belly and a naked scaly tail. They weigh about 12 to 16 ounces and are 13” to 18” long as adults, including the tail. Rats typically breed in the spring and fall. The average female has 4 to 6 liters per year with about 6 to 12 young per liter. The young are born within 23 days after mating.Norway rats could be found in and around homes, garages, sheds, commercial establishments, sewers, alleys, junk yards, fields, landfills and ravines. They can access a structure via a quarter size hole and through a 1/2? gap under a door. They could also gain entry by gnawing, climbing, jumping or even through sewer lines. Once inside, Norway rats usually inhabit the lower floors by nesting inside walls, cluttered storage areas, and underneath equipment/appliances. Noises (squeaks, scurrying, etc.), droppings (about 3/4” long with blunted ends), rub marks, tracks, gnaw marks, and fur are all signs of a rat infestation.Outside, Norway rats will dig burrows into the ground which are generally 12” to 18” deep and about 3’ long. There are typically distinct paths leading to the burrow opening. Since they are great diggers, they could also build their nests inside holes around building foundations, in stream banks, under slabs as well as under piles of wood and other debris.Norway rats are mainly active at night and will travel 100 to 150 feet from their nest in search of food and water. They are omnivorous, but prefers to feed on proteins like meat, fish, pet food and insects. They will even eat their own young if the need arises. Rats will often hoard food in hidden areas for use when food supplies run short. They require about a 1/2 to 1 ounce of water daily when eating dry foods but need less when moist foods are available.To make up for their poor eyesight, they have a keen sense of hearing, smell, taste and touch. They constantly explore their environments and are wary of anything new in their environment which makes baiting and trapping rats difficult as they may first avoid any attractants used.