What Does a Mouse Exterminator Do? Inspection, Treatment and Follow-Up in Canada

TL;DR

• A mouse exterminator starts with an inspection that maps where mice get in, travel, nest and feed, inside and outside your home.
• Then the job has three parts: close the way in, remove the mice already inside, and come back to check.
• Gaps should be sealed with materials mice can't chew, such as metal, concrete or metal mesh. Expanding foam, rubber and wood are ineffective because mice gnaw through them (UC IPM).
• Inside, traps go against walls and along the paths where droppings were found. Outside, locked bait stations go around the building.
• A single visit is rarely the whole job. Traps should be reset after 2 to 3 weeks to catch young mice as they mature (Health Canada).
• Need help? Get a quote from a recommended local exterminator through Pest Agent's referral form.

A mouse exterminator does much more than leave poison behind the fridge: the visit runs from an inspection of how the mice get in, to sealing gaps, setting traps or locked bait stations, and a return visit to check the results. The poison-only picture is a common misconception, and it leaves the same gap open for the next mice.

Canadian rules shape the job as well. The products a professional applies must be registered by Health Canada, and the person applying them needs a provincial licence. Most of what decides the outcome still happens during the inspection, when the technician maps where the mice enter, travel and nest.

What Does a Mouse Exterminator Do During the Inspection?

A mouse exterminator starts with an inspection that maps where mice get in, travel, nest and feed, inside and outside your home. Every later step depends on it: traps go where mice travel, bait stations go where they feed, and sealing work targets the exact gaps they use. Canadian companies describe this first step as a full interior and exterior inspection, often documented in writing.

Signs of Mice

Signs of mice tell the exterminator how big the problem is and where the activity is concentrated. Health Canada lists the main ones: droppings and urine, gnaw marks, damaged food packages, scratching sounds in the walls at night, tracks on dusty surfaces, and holes in or around foundation walls.

Entry Points

Entry points are the main target of the inspection, because removing mice without closing the way in only makes room for new ones. Health Canada notes that mice can squeeze through cracks as small as a dime, and that even the small gap under a worn door threshold lets them in. UC IPM recommends closing every opening larger than 1/4 inch (about 6 mm). The exterminator checks door sweeps, foundation cracks, and the spots where pipes, vents and utility cables enter the house. For a do-it-yourself check, see how to find mouse entry points.

Nesting Areas

Nesting areas show where the mice spend their time. Mouse nests are made of finely shredded paper or other soft fibres (UC IPM), and companies report checking kitchens, attics, basements, wall voids, ventilation systems and the space behind appliances. Finding the nests tells the exterminator where to concentrate traps.

Species Identification

Species identification matters because the two mice most often found in Canadian homes carry different risks. According to Health Canada, the house mouse has large ears and is light brown to dark grey with a lighter belly, while the deer mouse is brown or grey with a white belly, white feet and a white underside on its tail. Health Canada calls the deer mouse the most common carrier of hantavirus, which changes how droppings and nests are cleaned.

Treatment Plan

The treatment plan turns the inspection into a list of actions: which gaps to seal, how many traps or stations to place and where, and when to come back. Several Canadian companies describe documenting their findings in an inspection report. Ask for the plan in writing, so you know what was done, what products were used and what you are expected to do on your side.

What Do Exterminators Do for Mice After the Inspection?

Exterminators do three things for mice after the inspection: they close the way in, remove the mice already inside and come back to check. Most companies combine these steps in one plan rather than relying on a single method, an approach often called integrated pest management.

Sealing Entry Points

Sealing entry points (also called exclusion or rodent proofing) is what keeps the problem from starting over. A good exterminator seals gaps with materials mice cannot chew, such as metal, concrete or metal mesh. UC IPM warns that plastic screening, rubber, vinyl, expanding foam and wood are ineffective because mice gnaw through them. Some companies seal small gaps themselves and recommend a contractor for larger structural repairs, so ask who does which part.

Indoor Trapping

Indoor trapping removes the mice that are already inside. Health Canada suggests setting 1 trap per metre along walls, or 5 to 10 traps near each visible mouse hole, and checking all traps daily. Professionals place them against walls, behind objects, in dark corners and along the paths where they found droppings, because mice travel along walls rather than across open floors.

Exterior Baiting

Exterior baiting places locked bait stations around the outside of the building, so mice feed on the bait before they reach the walls. Canadian companies describe these as anchored, tamper-resistant stations holding Health Canada approved bait, placed around the perimeter. Inside the home, many professionals limit bait to stations or to voids that people and pets cannot reach.

One-Way Doors

One-way doors are a removal method some wildlife companies use: a small door installed over an entry point lets mice leave the building but not come back in.

Habitat Changes

Habitat changes are the part of the plan that falls to you. Exterminators typically recommend storing food in sealed containers, fixing leaks, clearing clutter, keeping firewood off the ground and trimming vegetation away from the house. Some companies make their guarantee conditional on following these recommendations, so read the terms.

Droppings Cleanup

Droppings cleanup is offered by some companies, but not all, so ask before the visit. The Public Health Agency of Canada advises never sweeping or vacuuming droppings: wear rubber or plastic gloves, spray them with a disinfectant or a mix of 1 part bleach to 9 parts water, and let it soak 10 minutes before wiping. Read more in do exterminators clean mouse poop.

Follow-Up Visits

Follow-up visits confirm that the treatment worked. The technician checks traps and bait stations, removes captured mice, looks for fresh signs and adjusts the plan. Health Canada recommends resetting traps after 2 to 3 weeks to catch young mice as they mature, which is one reason a single visit is rarely the whole job.

What Do Exterminators Use for Mice?

Exterminators use a short list of tools for mice: snap traps, multi-catch traps, locked bait stations with registered rodenticides, and metal exclusion materials. The skill is less in the products than in where and how they are placed.

Snap Traps

Snap traps are the basic tool of mouse control. Health Canada says snap traps and electronic traps are easy to use and very effective if they are well positioned and set properly. UC IPM notes that the best bait is often the food the mice are already eating, and peanut butter is a popular choice. If you want to compare models yourself, see our picks for the best mouse trap.

Multi-Catch Traps

Multi-catch traps hold several mice without being reset, which UC IPM says reduces the labour involved. Some companies use them in commercial buildings. The CDC advises against live traps at home, because trapped mice can urinate from stress and raise the risk of infection, so ask how often a live-catch trap will be checked if one is used.

Tamper-Resistant Bait Stations

Tamper-resistant bait stations are locked boxes that hold the bait so children, pets and wildlife cannot reach it. Health Canada requires poisoned bait to be used in a tamper-proof bait station in areas accessible to children and pets, and domestic rodenticides sold to homeowners must always be used in bait stations.

Commercial-Class Rodenticides

Commercial-class rodenticides are the main product difference between a professional and a homeowner. Health Canada states that commercial class products must be applied by a certified professional, and that commercial applicators have access to bait types homeowners cannot buy, such as loose pre-mixed bait. Bait is slower than traps: UC IPM notes that rodenticide baits generally take several days to work, and that poisoned mice can die inside walls and cause odours, which trapping avoids. Many companies describe rodenticide as a last resort, and some offer rodenticide-free programs.

Exclusion Materials

Exclusion materials are what the exterminator uses to seal the house. The ones recommended by Health Canada, the Public Health Agency of Canada and UC IPM include steel wool around pipes before caulking, fine metal mesh over dryer vents, attic vents and soffits, metal weather stripping under doors, wire screening, metal flashing and cement. Companies also describe galvanized or copper mesh, door sweeps and professional sealants. UC IPM notes that steel wool works as a temporary plug but may rust over time.

Remote Monitoring

Remote monitoring uses sensors in traps or stations that report activity, so the company knows when and where mice are caught. It is mostly sold to businesses such as restaurants and food facilities, where pest records are needed for inspections, but it is worth asking about if you have a large property.

What Rules Limit What a Mouse Exterminator Can Use in Canada?

Canadian rules limit what a mouse exterminator can use through federal product registration and provincial licensing. Health Canada's Pest Management Regulatory Agency (PMRA) registers each product, and each province licenses the people and businesses that apply them.

Provincial Licences

Provincial licences are the first thing to check. In Ontario, you need a pesticide exterminator licence to apply pesticides commercially, structural extermination is one of the licence types, and an extermination business needs a pesticide operator licence. Operator licences issued since September 2018 can be searched on the Access Environment website. In Quebec, the government advises choosing a company that holds a C5 or D5 extermination permit, with employees who hold a CD5 certificate.

PCP Numbers

PCP numbers show that a product is registered in Canada. Health Canada advises always looking for a Pest Control Products (PCP) number on the label. You can ask the exterminator which products they plan to use and check the label yourself.

Second-Generation Anticoagulants

Second-generation anticoagulants are the strongest rodenticides, and Canada keeps them out of homeowners' hands. Health Canada prohibits brodifacoum, bromadiolone and difethialone in domestic products, and domestic rodenticides must be block or solid baits used in bait stations. Loose forms such as pellets, treated grain and liquid baits are not allowed for domestic use. This is one reason a professional's toolkit differs from what you find at the hardware store.

British Columbia Restrictions

British Columbia goes further. Since January 21, 2023, the sale and use of second-generation anticoagulant rodenticides (SGARs) is banned for the public and most commercial operations in the province. Only essential services such as hospitals and food production can still use them, with a certificate and licence, a site-specific integrated pest management plan and records of each use. In practice, a mouse exterminator in a BC home relies on exclusion, traps and other baits.

What Should You Do Before and After a Mouse Exterminator Visit?

The visit works best when you make the house easy to inspect and keep up the changes the exterminator recommends. Your part matters as much as the products.

Before the Visit

Before the visit, give the technician access to the places mice use: the basement, the space under sinks, the garage, the attic hatch and the area behind the stove and fridge. Note where and when you have seen mice or droppings. Our guide on how to prepare for a mouse exterminator has a full checklist.

Children and Pets

Children and pets should stay away from traps and bait stations. Ask the technician to show you where each one is placed, which product is inside, and whether any station is inside the living space. Keep the product labels or the service report, so you have the PCP number on hand if a child or pet ever gets into bait.

Knowing the Mice Are Gone

Knowing the mice are gone comes down to time and evidence. The CDC suggests that if no mice are captured for a week and there are no new signs, the mice are gone. How long it takes to get there depends on the size of the infestation, as explained in how long it takes to get rid of mice.

If Mice Come Back

If mice come back, the usual cause is an entry point that was missed or reopened. Check your warranty: one Toronto company, for example, advertises a 100-day warranty with free re-treatment, and terms vary between companies. Our guide on why mice come back after extermination covers the common causes.

Hiring a Mouse Exterminator

Hiring a mouse exterminator is easier once you know what the job involves: look for a provincial licence, a written inspection report, real sealing work and a clear warranty. Our guide to mouse pest control and finding a professional explains how to compare companies, and our page on mouse exterminator cost covers pricing (prices vary by city and job size). You can also get a quote from a recommended local exterminator through Pest Agent's referral form, or browse all our mice guides.