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Norway Rat


Also called the brown rat, house rat, barn rat, sewer rat, gray rat, or wharf rat, it is a slightly larger animal than the roof rat. The nose is blunt, the ears are small and close set. The tail is scaly, semi-naked and shorter than the head and body combined. Adult Norway rats weigh an average of about 1 pound. Their fur is coarse and usually is brownish or reddish-gray above, and whitish-gray on the belly. Black coloured Norway rats can occur in some locations.

Also called the brown rat, house rat, barn rat, sewer rat, gray rat, or wharf rat, it is a slightly larger animal than the roof rat. The nose is blunt, the ears are small and close set. The tail is scaly, semi-naked and shorter than the head and body combined. Adult Norway rats weigh approximately one pound. Their fur is coarse and usually brownish or reddish-gray above, and whitish-gray on the belly. Black coloured Norway rats can occur in some locations.

  • Feeding: Norway rats will eat almost anything, but prefer to have cereal grain, meat, nuts, fish, and fruit.
  • Hibernation: Norway rats do not hibernate.
  • Nesting: Nests are usually found in underground burrows or at ground level. Nests may be lined with cloth, paper, or other fibrous material.
  • Reproduction: Females mature at 3 months of age and may come into heat every 4 or 5 days. Breeding often peaks in spring and fall, on average a female Norway rat has 4 - 6 litters a year, with 6 – 12 young per litter.

Norway Rats can:

  • Pass through any opening larger than ½ inch (1.3 cm)
  • Walk along horizontal wires and climb vertical wires
  • Climb the inside of vertical pipes 1 ½-4 inches (3.8-10 cm) in diameter
  • Climb horizontally on any type of pipe or conduit
  • Jump vertically at least 36 inches (0.9 m) above a flat surface
  • Reach about 13 inches (33 cm) above a flat surface
  • Dive and swim underwater for as long as 30 seconds
  • Swim up through the water seal, or trap, of toilets
  • Swim as far as ½ mile (0.8 km) in open water
  • Gnaw and leave marks on almost anything, including wood, chip board, lead pipes, cinder blocks, asbestos, aluminum, sheet metal, glass, and sun-dried adobe



  • Droppings along runways, in feeding areas and near the rat’s shelter. Fresh droppings are soft
  • Urine along traveled pathways or in feeding areas. Both wet and dry rat urine glows under ultraviolet light
  • Runs or burrows next to walls, along fences, next to buildings or under bushes and debris. Rats memorize these pathways and use the same routes habitually
  • Smudge marks or rub marks on beams, rafters, walls, pipes and other fixtures. These are the result of oil and dirt rubbing off the rats’ fur along frequently traveled routes

Rats are looking for food and shelter all year round.  If you cut off access to those two things, it will help solve your rodent problem.

  • Clean areas under stoves, refrigerators and dishwashers.
  • Store dry food (rice, pasta and grains), dry pet food and birdseed in metal, glass or plastic containers.
  • Empty pet food dishes after feeding and wash every night. Place bird feeders with seed away from the house.
  • Store lumber, firewood and compost away from the house. Elevate lumber and firewood on pallets.  Use thick plastic or metal trash cans with tightly fitting lids.
  • Rake, collect and remove fruit, nuts and other foods that have fallen out of plants or trees.
  • Repair all small holes in foundation, walls, basements, etc. Use caulking, a concrete patch, course steel wool or copper mesh.  You can also fasten a sheet metal plate or cement over masonry.
  • Properly dispose of garbage.



  • To prevent rats from coming indoors, make sure doors and windows have fine-mesh, well-maintained screens.
  • Cover vents, ducts, holes around electrical conduits, floor drains and other openings with copper or aluminum screens, or with metal coverings. Inspect your foundation, walls, and basement for any rodent holes or cracks.
  • Plug these holes with concrete, caulking, copper or aluminum mesh or steel wool.



  • Put food away each day, and do not leave glasses of water out overnight.
  • Keep food preparation and serving surfaces clean, and clean behind refrigerators and stoves.
  • Dispose of garbage regularly and use tight fitting lids on garbage receptacles. Don’t leave food overnight in pet food bowls.



  • Clip grass and weeds short, and thin shrubbery until the ground underneath is visible.
  • Trim shrubs away from walls.
  • Avoid over-irrigation of lawn and garden and ensure proper soil drainage.
  • Move lumber piles, firewood, compost and other potential rodent habitats away from the walls of your home.

Exclusion is the best control method. All food must be stored in properly sealed jars or tins and kept in containers with tight-fitting lids. Garbage should be prevented from accumulating. Seal all openings to the outside, including wood around doors and windows; repair masonry and seal openings for utility lines, conduits, and drains. Inspect and check outdoor compost areas. Rodent baits, traps, or glue boards are all possible options to control the rat population.


The use of labelled rodenticide in exterior bait stations around a property is useful in eliminating an infestation. The use of snap traps with peanut butter bait, chocolate syrup or bacon grease work well. Be sure to pre-bait snap traps.

Is Alberta still a rat free province?

  • Alberta’s “rat-free” status still stands strong with its aggressive rat control program to keep the vermin outside of the borders. Poulin’s Pest Control helped write a piece of Canadian history; our efforts and talents were the main result of Alberta becoming a “rat free” province. It’s estimated one pair of reproducing rats could lead to a colony of 15,000 rats in a year. This showcases the importance of calling an exterminator if you see any rats.


Where should I place baits, bait stations, or traps?

  • Place bait stations and traps where there are signs of heavy rodent activity. (feces, chew marks, urine stains, hair, scratching and/or squeaking sounds at night). Placement will usually be against a wall and out of reach of children, pets, and non-target animals. Rats and mice have limited vision so they always follow lines such as walls. Leave mouse traps undisturbed for at least two days before moving to a new location.


Can I touch rodent bait?

  • All rodent baits can be safely handled but always wash your hands with soap and water after handling rodent baits.


How do I keep rodent baits away from children & pets?

  • Bait stations are the ideal device to add safety to rodent control. They are extremely durable, tamper resistant and can even be anchored to ensure they will not be picked up or moved. There are also many types of effective traps to consider instead of baits. Place the bait stations under stoves, dishwasher and behind fridges.


I used the bait: Why do I still have rodents?

  • It can take up to 10 days to kill rats or mice.
  • Many rats and mice have developed a resistance to warfarin. Switch to a single feed anticoagulant rodenticide.
  • Not enough bait was used. Rat and mice infestations can be very large (almost always larger then you would expect – rarely just one). Continue to refill the bait station as long as they are eating the bait as it may take time to reduce the population.
  • Rodents can and will move pellets to another location and cache the bait. Switch to a single feed anticoagulant block bait that will be ingested right inside the bait station.
  • Clean up areas where rats and mice live and breed and remove other all other food sources.
  • To ensure that new rodents are not gaining access make sure all small openings around your house and foundation are sealed especially around pipes, wires, windows, and doors.

Rats and mice love clutter and hate open spaces. Basements, storage areas, and garages often become rodent havens due to accumulated boxes, furniture, and collectables. Clean and organize these areas as soon as possible if you see signs of rodent activity.

Norway Rat Information Download View
Rodent Treatment - Preparation Sheet Download View
Bait Suggestions Download View
Preventing Rats and Mice From Entering Your House Download View
Tips for Mouse & Rat Traps Download View
Live Trapping Tips Download View