Rats are a common pest in urban areas like Thunder Bay. The Norway rat, also known as a brown rat, is the most common rat in Thunder Bay. Rats are pests and can be found year-round. They live outdoors and begin to migrate indoors when cool weather approaches. Rats nest in any safe location where food and water are available such as under woodpiles, in abandoned vehicles, between walls or under floors in garages or sheds. Outdoors they will burrow into the ground close to their food source. Rats are nocturnal animals, meaning they are most active at night. Rats will become active during the day if food and water are scarce, or if large infestations occur.

To control rats and keep them off your property and out of your home, you have to get rid of the three things they need to survive: food, water and shelter.

Rat prevention and control video


Risks from rats

The risk of rats spreading disease in the community is low. However, rats can be a nuisance. They can do a lot of damage to properties.

Steps to control rats

Rats can quickly increase in numbers because they are fast breeders. It is unlikely that we will be able to get rid of all the rats but we can try to control the number of them.

Step 1: Look for Evidence

Look for other clues that rats are living on or around your property including:

  • Droppings - Rat droppings (feces) are larger than mouse droppings, look like pill capsules and are often found close to garbage.
  • Burrows - Norway rats prefer to live, sleep and raise their young in underground burrows. The entrance to a burrow is a small hole in the ground. Look under shrubs, porches, decks and in long weeds and grasses for entrances to burrows. Each burrow has one entrance and one or two exits.
  • Gnaw marks - Rats can chew and gnaw through many different materials.
  • Trails - Rats are creatures of habit. They use the same pathways many times a day.
  • Grease marks - Whenever a rat rubs up against a surface, such as a wall, it leaves a grease trail.

Step 2: Clean-up

Important thing to help keep your home and yard clean and tidy to discourage rats:

  • If you store wood or other items in piles in your yard, keep them away from walls. Elevate any lumber or firewood 12" off the ground.
  • Control grasses, weeds, shrubs and bushes.
  • Get rid of vines that rats can use to climb up into your roof.
  • Trim low-lying shrubs and bushes.
  • Keep the ground bare around the foundation of your home.
  • Keep gardens/lawns free of weeds and garbage.

Rats communicate and attract each other through urine and droppings:

  • Use a mild bleach solution (one part bleach to 10 parts water) to dampen droppings before you sweep them up.
  • Try to clean-up dark greasy track marks.
  • Wash down areas where rats have been with water and a mild bleach solution.
  • Get rid of garbage and clear out items.

Step 3: Limit Food Source

Rats only need one ounce of food per day to survive. They need to drink every day. Do not provide food and water for rats on your property.

  • Keep garbage in a tightly sealed garbage bin made of hard plastic or metal.
  • Make sure rats cannot access your compost.
  • Clean up any fruits or vegetables that fall off trees or plants.
  • Do not use bird feeders. If you want to use bird feeder, put a catch basin under it to collect spilled seeds or clean under the bird feeder at least once a day.
  • Do not leave pet food outside.
  • Clean-up any dog feces on your property.
  • Remove water sources on your property.
  • Turn off and dry out water fountains, remove birdbaths and turn over containers that can hold water.

Step 4: Keep Rats Out of Your Home

Use approved traps and poison found at hardware stores to eliminate rats. Rats can get through a space the size of a quarter.

  • Seal all holes and cracks in foundations, walls, floors, underneath doors and around windows. Use metal door sweeps under door openings.
  • Make sure rats cannot climb into pipes and other exhausts around the outside of your home.

Step 5: Eliminate Rats

Use traps and poison found at hardware stores to eliminate rats. It is important that you use caution - traps and poison can be dangerous to people and other animals. Place traps and poison in areas where children and animals cannot access them. If you have a large infestation that you cannot control, hire a licensed pest control company.

More information

Visit the Thunder Bay District Health Unit's website and the Canadian Government's website to learn more about preventing and controlling rats.

Contact information

Thunder Bay District Health Unit's Public Health Inspector


or toll-fee 1-888-294-6630

City of Thunder Bay's Infrastructure & Operations Dispatch


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