Identify Your Pest Rodents Norway rat
Norway rat
Rattus norvegicus · Also called: Brown rat, sewer rat, wharf rat
The Norway rat is a large, thick-bodied rodent found in cities across much of North America, but Alberta has kept it from becoming established since 1950. When Albertans report a rat, it is usually a large mouse, ground squirrel, pocket gopher or muskrat.
Size About 40 cm long, with a 15 to 22 cm tail
Colour Brownish grey back fading to a pale grey or off-white belly
Key feature Thick body with a scaly, nearly hairless tail a bit shorter than the body
Season Not established in Alberta; a lone rat can arrive at any time of year
Where Foundations, farm buildings, feed storage and transport yards, if present
What it looks like
A Norway rat is much bigger than any mouse. An adult is about 40 cm long from nose to tail tip and can weigh close to half a kilogram. It has a blunt snout, small ears, small dark eyes and coarse grey-brown fur that is lighter underneath. The tail is thick, scaly, nearly hairless and a little shorter than the head and body.
Rats dig burrows with clean, round openings about 5 to 7.5 cm wide, often along foundations. Fresh droppings are glossy black and capsule shaped with blunt tips, about 12 to 15 mm long, two to three times the length of a mouse dropping.
Often confused with
Muskrat
Bushy-tailed woodrat (pack rat)
Pocket gopher or ground squirrel
Signs to look for
Large droppings
Burrows by buildings
Heavy gnawing
Grease marks and odour
Risks and damage
Where rats are established, they can spread diseases such as leptospirosis and salmonellosis through urine and droppings, and they carry fleas. They gnaw wiring, pipes and wood, dig under foundations and spoil stored food and feed. This is why Alberta works hard to stay rat-free. Norway rats are a declared pest under Alberta’s Agricultural Pests Act, so landowners must control them if they are found.
In Alberta
Alberta has no established rat population. Since 1950, provincial and municipal staff have stopped rats from settling in and check every report. Many rats found in recent years rode in on trucks or other vehicles. Any suspected rat in Alberta should be reported to 310-FARM (3276).
Norway rats first reached Alberta’s eastern border in 1950. The province set up a rat control zone along that border, and Alberta has kept rats from becoming established ever since.
How to keep them out
Check vehicles after trips
Store feed and grain securely
Remove shelter
Rat-proof buildings
When it is time to bring in a professional
If you think you have seen a rat, report it to Alberta’s Rat Control Program at 310-FARM (3276), with a photo if you can. Provincial and local staff follow up on every report. If the signs turn out to be from mice, voles or gophers, Technica’s licensed technicians can identify the animal and deal with it.
Frequently asked questions
Are there really no rats in Alberta?
Alberta has no established rat population. Rats still turn up every year, often as hitchhikers on trucks or in cargo, and small infestations are sometimes found. These are tracked down and removed through the provincial Rat Control Program.
What do people in Alberta usually mistake for a rat?
Usually a muskrat, seen near water or crossing a road. Other common mix-ups are Richardson’s ground squirrels, pocket gophers, large mice and, in the foothills and mountains, native bushy-tailed woodrats. Check the tail. A Norway rat has a long, round, scaly tail with very little hair.
Can I keep a pet rat in Alberta?
No. Alberta law bans rats as pets, including white and fancy rats, and they cannot be brought in or sold here. Only permitted zoos, colleges, universities and research labs may keep them. The ban helps stop escaped pets from starting a wild rat population.