Managing rat and mouse pests

Rats and mice can cause property damage and health problems. Learn how to use Integrated Pest Management (IPM) to deal with these pests.

On this page:


Prevent rats and mice

Prevention is the most effective way to control rats and mice.

Use prevention techniques around existing buildings or incorporate them into the design of a new building.

  • Seal all openings that are bigger than 6 mm (1/4 inch) with durable materials:
    • Stuff steel wool around pipes and then seal with caulking or plaster
    • Cover dryer vents, attic vents and soffits with heavy 1/4 inch wire mesh
    • Repair cracks in foundations
    • Install metal weather stripping under doors, and weather stripping around windows
    • Install chimney caps
  • Install sheet metal kick plates on the exterior of doors to prevent rodents from gnawing
  • Build outbuildings like sheds on concrete pads, not bare ground
  • Prune back branches that hang over balconies, eaves and roofs
  • Regularly inspect and repair entry points
  • Keep all garbage in containers with tight-fitting lids
  • Keep rodents out of your backyard composter:
    • Use composters that contain the compost off the ground. If your composter rests on the ground, install a layer of heavy metal mesh between the soil and the composter
    • Keep a tight-fitting lid on the compost bin
    • Don’t put meat, dairy products or eggs in backyard composters
  • Remove any food outside:
    • Fallen fruit or nuts
    • Birdseed and chicken feed around feeders
    • Don’t feed stray or wild animals
  • Clean up any leftover food after your pet is done eating
  • Clean up pet waste
  • Keep food prep and storage areas clean:
    • Store dry goods, birdseed and dry pet food in hard-walled containers with tight-fitting lids
    • Avoid leaving produce out. Keep it in the refrigerator
  • Eliminate water sources:
    • Fix leaky taps, sweating pipes and open drains
    • Cover pools and hot tubs when not in use
  • Remove unused clutter in and around buildings
  • Keep building perimeters clear of junk and debris
  • Cut tall grass and weeds back from buildings
  • Keep bushes and trees around buildings trimmed so that 15 to 20 cm (6 to 8 inches) above ground is clear
  • Store firewood and lumber away from buildings and at least 30 cm (1 foot) off the ground

Clean up areas where they’ve been as rodents are attracted to the smells left behind by other rodents. It's also important to clean these areas to protect your health because rodents can transmit diseases.

  • Find out how to clean up after rodents safely:
    • Get rid of droppings, nesting material and damaged food
    • Clean urine stains, rub marks, tracks, and any areas where rodents have been with a mild bleach solution

Rodents will cross property lines. Encourage your neighbours to also take preventative steps to keep rodent problems from spreading around your community:

  • Share rodent prevention techniques
  • Help neighbours who need assistance
  • Organize community efforts to prevent rodent problems in public spaces

 


Identify rats and mice

Signs of a rodent problem

Rats and mice are most active at night, so it can be hard to spot them. But there are signs to watch out for including:

  • Droppings and urine stains
  • Burrows, holes or nests
  • Runs and tracks
  • Greasy rub marks and chew marks
  • Chewed food packages
  • Noises

Type of rodent

There are many kinds of rodents in B.C., but only three typically cause problems for people. Make sure to identify the type of rodent you are having problems with so you can use the best methods to deal with them.

  • Droppings are 15 to 20 mm (3/4 inch) long with rounded ends
  • Measures 30 to 45 cm (12 to 18 inches) from nose to end of tail
  • Blunt nose and ears that are relatively small for the size of its head
  • Tail is shorter than the length of its body (including its head)
  • Generally live at ground level and build elaborate systems of tunnels and burrows
  • Prefers moist conditions like crawl spaces and building perimeters
  • Droppings are 10 to 15 mm (1/2 inch) long with pointed ends
  • Slimmer than the Norway rat
  • Measures 33 to 43 cm (13 to 17 inches) from nose to end of tail
  • Pointed nose and large ears
  • Tail is longer than its body and head put together
  • Agile climbers that prefer to live higher up in trees, vines and other dense vegetation
  • Often nests in ceilings and attics
  • Droppings are around 6 mm (1/4 inch) long with pointed ends
  • Measures 15 to 17 cm (6 to 7 inches) from nose to end of tail
  • Pointed nose, relatively large ears and a nearly hairless tail
  • Nests in hidden, enclosed spaces using shredded paper, insulation, string or other soft materials

 

Click the image below to enlarge.

Comparison of a Norway rat, roof rat, house mouse and their droppings.

Problem areas

Rats and mice need food, water and shelter to live. They can also squeeze through very small holes or cracks. Identifying and eliminating their access to these things is important in managing a rodent problem.

Mice can gain access through a dime-sized opening, while rats only need a quarter-sized hole to get in.

Look for:

  • Any gap or hole inside or outside your building that is 6 mm (1/4 inch) or bigger
    • Don't forget to check the roof
  • Food and water sources
  • Areas where rodents could live or hide
  • Vegetation touching or overhanging the building

Consider hiring a licensed pest control company to help you identify the problem areas for your building and to design a long-term IPM strategy for you.


Threshold for rat and mouse control

As soon as you notice signs of rats or mice, it’s time to take action. Rats and mice reproduce quickly. Ignoring an occasional invader can result in a much more damaging infestation.

Rats and mice can:

  • Damage property by chewing on materials like insulation, siding and wallboard
  • Start electrical fires by gnawing on wiring
  • Eat and contaminate stored food
  • Transmit diseases

Control rats and mice

When you have a rodent problem, you will need to combine prevention and control methods to get rid of the problem and stop it from happening again.

Before you start your control program, make sure you have identified what type of rodent you are having a problem with, so you can choose the best options.

If you are unable to get rid of the rodent problem on your own, hire a licensed pest control company. They have the knowledge and expertise to effectively manage the pest. 

Control options

There are several options to consider for controlling rats and mice:

When choosing a control method, use rodenticide alternatives like snap traps whenever possible to avoid harming people, pets, birds and other wildlife. 

Traps

The best way to get rid of rats or mice is by using traps. Traps are effective and are less likely to harm children, pets or wildlife. Several types of trap are available:

  • Snap traps
  • Electronic traps
  • Live traps
  • Glue traps

Snap or electronic traps are the best option because they are effective and kill rodents quickly and humanely. Live traps and glue traps may cause significant stress and suffering for the animals that are caught.

If you release a live rodent, consider where it will go. It may return or cause a problem for your neighbour.

How to use traps

  • Choose traps for the type of rodent you are dealing with. Rat traps and mouse traps are different sizes, and the wrong one won’t work
  • Always read and follow the manufacturer’s directions on how to use your trap
  • Set traps along walls where rodents travel
    • Put the bait side of the trap toward the wall for uncovered traps
    • Put the entrance of the trap parallel to the wall for covered traps
  • Protect children, pets and wildlife from getting injured by traps. Put them in bait stations or in inaccessible areas
  • Place traps about one meter apart
  • Use bait like dried fruit, peanut butter (mixed with oats), cheese, marshmallows, onions or any other food they've already been nibbling on
  • Leave the baited traps out for several nights before setting them, so the rodents get used to them
  • Check traps daily
  • Wear gloves to handle the trap and all dead rodents
  • Wrap the dead rodent in plastic and put it in the garbage
  • Re-use traps. They are more attractive to other rodents than new traps
  • Reset traps in 2 to 3 weeks to catch maturing rodents. You won’t get long-term control if you don’t catch them all

 

Rodenticides (rodent poisons)

Rodenticides are high-risk pesticides. They are organized into two classes based on who can use them. The product label will say whether the rodenticide is domestic or commercial class.

  • Domestic class rodenticides are for personal use in and around the home
  • Commercial class rodenticides are for use only by trained, professional pest control operators and farmers

Risks of rodenticides

Rodenticides are highly toxic and should only be considered as a last resort because of the risk they pose to people, pets and wildlife.

Because of their risks to wildlife many rodenticides have restricted uses in B.C.

Direct poisoning

  • Pets, children and wildlife can die or be seriously hurt if they eat the poisoned bait

Secondary poisoning

  • Natural predators like hawks and owls can die or suffer long-term effects from eating poisoned rodents
  • Losing these natural rodent predators can make the pest problem even worse

A flow diagram showing secondary wildlife poisoning from consumption of rodents poisoned by rodenticides

When using rodenticides in and around the home:

  • Always read and follow the label directions
  • Choose least-toxic formulations first, like corn cellulose
  • Only use domestic class rodenticides in tamper-proof bait stations
  • Never place rodenticides in a place where children, pets or other animals can access the bait
  • Never scatter poison baits over the ground or inside a building
  • Wear gloves when handling rodenticides
  • Properly dispose of any leftover bait and dead rodents

Be aware that rodenticides can cause rodents to die and decompose in an inaccessible place which leads to a terrible smell and insect infestations.

Ultrasonic repellents

Ultrasonic repellents may work at first, but rodents get used to the sound and learn there's no harm associated with it.

Predators

Predators can help reduce rat and mouse populations.

 

Some cats will catch mice or rats, but they are typically not an effective way of controlling an infestation. The presence of a cat may help keep rodents away. Remember that cats will also kill birds.

A few precautions about cats catching rodents:

  • A cornered adult rat can seriously injure a cat
  • Cats may bring live rodents into living spaces
  • Rodents often carry parasites that can be passed on to cats

Raptors like owls and hawks are natural predators of rats and mice. Encourage raptors in your area to help keep rat and mouse populations in check.

  • Keep, restore or enhance raptor habitat features:
    • Nesting sites
    • Roosting and perching sites
    • Foraging areas
  • Reduce the risk of accidental mortality, such as collisions with wires or windows
  • Avoid using herbicides that may reduce habitat
  • Avoid using anticoagulant rodenticides. They can cause secondary poisoning of raptors

 


Monitor and evaluate control measures

Monitor and evaluate how well your rodent control program is working.

  • Is your trap bait working?
    • Finding a bait that rodents like can take some time. You may need to try several different kinds before finding one that is effective
  • Are your traps or bait stations in the right place?
    • If your traps aren’t catching the rodents or your rodenticide bait isn’t being eaten, you might need to move the trap or bait station to a better location. Look for areas where they’re travelling the most
  • Have you gotten rid of them all?
    • Rodents take 2 to 3 weeks to mature, so put traps out every 2 to 3 weeks until you don’t catch any more

Once your rodent problem is under control, revisit preventative measures to stop it from happening again. Continue to monitor for problem areas or other signs of rat or mouse pests.