Norway Rats

(Rattus norvegicus)


Norway rats (Rattus norvegicus), also known as brown rats or sewer rats, can range in size from 13-18” in length, and in color from light reddish brown to black. This large rat has a blunt snout, small eyes, and small ears and covered with hair. The Norway rat lives in burrows outdoors or in and around stored items, wall voids and attics. The tail is dark on top and pale beneath. Norway rat droppings can be identified by their large size, about ¾” long, and their blunt ends. Other common signs of rat problems include:

  • Sightings of rats themselves (live or dead)
  • Tracks
  • Damage to food or food packaging
  • Growing damage and gnawing sounds
  • Burrows
  • Rodent odors
  • Dark rub marks from the fur and oils on the rodents


Rodents are the second most successful breeding mammal on earth behind Man. This means that a small infestation of rats will quickly and exponentially grow if not controlled. Two adult rats can become eight in less than 3 weeks.

Rodent gnawing habits can be unsightly and damaging to property. This can be a safety hazard, as their gnawing can also lead to fires if they chew through electrical wire insulation. Their droppings contaminate food and surroundings, and their burrows damage landscape and can lead to erosion.

Rats are medically important because of their ability to carry many diseases such as rat bite fever, Weil’s disease, rickettsia diseases, plague, and have been known to bite when threatened. Rat hair and excrement can also contaminate food, which can lead to severe food poisoning.


Exclusion, sanitation, and reduce harborage or shelter provide solutions to rodent pest management. Exclusion involves sealing voids, cracks, crevices, and other openings so rats cannot enter or nest in buildings. However, this can be difficult. Rats have a very soft skeleton, and can squeeze through openings only half an inch wide.

Sanitation involves eliminating food, harborage, and water sources that attract and sustain rat infestations. Common food sources around the home include pet foods, birdseed, garden seed, and improperly stored garbage.

Harborage reduction can be accomplished by trimming or eliminating excessive vegetation near buildings, such as tall grasses or bushes. Removing other harborage areas such as stored lumber, rock piles, old equipment and construction material can also deter rodent infestations. Rats will also burrow into soil or mulch, so keeping an eye out for burrows near your home can help identify a rat problem.

If you suspect rodent activity, call your local Cook’s office. Cook’s Pest Control offers expert rodent control, and our pest management professionals are thoroughly trained to address your rodent needs.


About Rodents

  • Both mice and rats invade a home looking for food and warmth.
  • They can contaminate more food than they actually eat.
  • Rats often start colonies in attics or under porches – and they’re harder to eliminate than mice.