Carpenter Ant Exterminator Greater Montreal: Prices and Effective Treatments in 2025

How can you identify a carpenter ant infestation in your home?

Key signs of infestation to watch out for

Visible presence of black or red ants

Carpenter ants are often mistaken for other species, but their larger size (6 to 12 mm) and habit of moving in a single-file line are telltale signs. You’ll typically spot them near woodwork, foundations, or in the kitchen. Learn more about their biological behavior.

Unusual noises coming from the walls

When the colony is well established, you may hear slight crackling or scratching noises in the walls, especially at night. These are the workers digging their galleries in the wood.

Sawdust (frass) and residue around baseboards

Unlike termites, which consume wood, these insects eject it. You'll notice small piles of fine sawdust, often accompanied by fragments of dead insects or wings.

Wings near windows or doors

Winged reproductives (also known as alates) usually emerge in the spring. If you find discarded wings indoors, it’s often a sign that a colony has already been established inside the house.

Differences between carpenter ants and termites

Distinctive physical features

- These ants have a well-defined segmented waist and angled antennae.
- The termitesThey have a more uniform size, straight antennae and a paler body.

Wood damage: recognizing the differences

- The galleries dug by the ants are smooth, clean and free of sawdust.
- Termites leave behind a labyrinth-like hollowed-out wood with muddy residues.

To find out more about pest control treatments registered in Quebec, visit

Health Canada's official page on pest control.

Why are carpenter ants a major problem in Greater Montreal?

Areas most at risk in Greater Montreal (Laval, North Shore, South Shore)

Particularly hard-hit neighborhoods (wooded, damp, older residential areas)

Carpenter ants mainly settle in areas with dense vegetation or high humidity. On the North Shore, sectors like Terrebonne, Mascouche, and Blainville are frequently affected. On the South Shore, they are commonly found in Brossard, Longueuil, Saint-Hubert, and eastern Châteauguay. In Laval and several surrounding boroughs of Montreal, properties near parks, wooded areas, or bodies of water are also vulnerable.

Older homes, built before modern insulation standards or affected by water infiltration, provide ideal conditions for these pests. Poorly ventilated crawl spaces, uninsulated garages, and exposed wooden structures are all common weak points.

What damage can they do to your home?

Frequent structural damage (frames, walls, insulation)

Unlike termites, which consume wood, the carpenter ants digging it out to form a gallery network. They weaken load-bearing elements such as joists, half-timbering and interior walls. If they attack a damp roof structure, the damage can progress rapidly without any visible signs on the outside.

These tunnels can also reach the wall insulation, creating areas of condensation, mold, or even thermal instability within the home. When they nest near electrical wiring, they also increase the risk of short circuits or fires. To learn more about best practices for preventative home maintenance, consult this government guide on residential upkeep in Quebec.

Financial risks associated with untreated infestation

A colony left untreated for several months can lead to costly repairs. In addition to extermination fees, you often have to factor in the costs of partial demolition, replacing damaged structures, and hiring professionals (engineers, electricians, carpenters). In the most severe cases, the total can exceed $10,000, not to mention the potential decrease in property value when selling the home.

How much will a carpenter ant exterminator cost in Greater Montreal in 2025?

Average price by type of treatment

One-time treatment (single intervention)

The cost of a one-time treatment for carpenter ants typically ranges between $375 and $1,000, depending on the severity of the infestation and the size of the area to be treated.

Recurring treatments (annual plans, preventive monitoring)

For homes located in at-risk areas or with a history of infestation, special annual packages with regular inspections and preventive treatments are often recommended. These packages generally cost between 700 $ and 1 800 $ per year.

Comparative table of extermination rates by sector

Price list are based on market observations in 2025. They may vary depending on the season, access to the infestation zone and the method chosen.

Factors influencing prices

• House size the larger it is, the longer and more costly the treatment.
• Severity of infestation A large colony with several nests requires more effort.
• Access to the nest More complex treatment if the nests are in the walls or roof.
• Method type ecological or thermal treatments can be more expensive.
• Season Demand is highest in spring and autumn.

What are the best methods for effectively exterminating carpenter ants in 2025?

Recommended professional methods

Targeted chemical treatment (sprays, insecticide gels)

Exterminators generally use approved products applied directly to infested areas. Visit residual spray act on the galleries, while the insecticide gels are placed at strategic entry points. These treatments have the advantage of acting quickly and limiting the spread of the colony.

Treatment with specialized baits and traps

Borax- or hydramethylnon-based baits are effective when properly placed. Worker ants carry the insecticide back to the queen, which helps eliminate the colony at its source. This type of intervention is often used alongside a chemical treatment or in more sensitive areas like kitchens.

Thermal method (heat treatment): advantages and limitations

Still not widely used in Quebec, this technique involves heating wooden structures at over 50°C to eliminate ants. It's effective and environmentally-friendly, but expensive. It requires specialized equipment and is not always suitable for inhabited or poorly insulated homes.

Natural and ecological methods: what are they really worth?

Effectiveness of home treatments (vinegar, essential oil, diatomaceous earth)

Some natural products can temporarily disturb ants, such as white vinegar or essential oils (peppermint, citronella). The diatomaceous earth can work on small colonies visible on the surface. However, these solutions do not eliminate the queen or secondary nests.

Limits of natural methods to control carpenter ants

These approaches are rarely sufficient against an established colony. Carpenter ants burrow deep into walls and can create several satellite nests. Without professional diagnosis, treatment may be ineffective, or even counter-productive if the colony disperses.

Conclusion: For lasting, safe control, the intervention of a certified exterminator remains the most effective solution.

Procedure for professional carpenter ant control

Step 1: Thorough inspection by the exterminator

Points checked during the inspection

The professional thoroughly inspects vulnerable areas of the home, such as woodwork, foundations, attics, and crawl spaces. They look for signs of activity like wood shavings, tunnels, or the presence of insect wings.

The importance of accurate diagnosis

A certified precise diagnosis allows you to locate main nests and satellites. This step is crucial for choosing the right intervention method the most efficient.

Step 2: Initial treatment tailored to the infestation

Choice of products and techniques

Depending on the layout of the site, the exterminator may apply an insecticidal gel, perform a targeted spray, or place specialized baits. The products used are approved by Health Canada and safe once dry.

Duration and follow-up of initial intervention

The average procedure lasts between 1 and 2 hours. A follow-up is generally planned 10 to 15 days at a later date to verify treatment efficacy.

Step 3: Preventive follow-up and post-treatment recommendations

Frequency of follow-up visits

In severe cases or when there’s a high risk of reinfestation, quarterly or semi-annual follow-ups may be recommended to prevent the colony from returning.

Do-it-yourself measures to prevent the return of ants

It is advisable to :

• Repairing water infiltration quickly.
• Pruning branches in contact with the house.
• Sealing cracks around foundations and windows.
• Avoid storing wood against exterior walls.

Prevention: how to protect your home from carpenter ants?

Simple preventive measures to be applied today

Maintenance of outdoor areas (dead wood, dampness, shrubs)

Carpenter ants often settle near homes where vegetation is dense and moisture is persistent. To reduce their presence, eliminate any excess moisture sources, trim back shrubs touching the walls, and avoid stacking firewood against the house.

Waterproofing and regular structural maintenance of your home

Regularly inspect foundations, window frames and attics. Seal cracks, replace damaged materials, and ensure a long service life. good ventilation in crawl spaces and basements to limit entry points.
You can consult the Health Canada's guide to carpenter ant prevention to learn more about these best practices.

Frequent mistakes to avoid attracting these pests

Firewood storage

Store your firewood at least three meters away from the house and elevated off the ground. Damp wood attracts colonies and makes it easier for them to access the interior.

Poor garden and gutter maintenance practices

Clogged gutters create moisture-prone areas, as do piles of leaves on the ground. Poor garden maintenance encourages nest formation, especially near wooden foundations.

Testimonials and user reviews of carpenter ant exterminators in Quebec

Concrete examples of successful interventions in Greater Montreal

Laval case study (Sainte-Dorothée)

In May 2024, a family from Sainte-Dorothée contacted a 911 Exterminator expert after observing the sawdust near the baseboards and heard some unusual scratching noises in the walls at night.

During the inspection, the technician discovered a main colony in the crawl space as well as two satellite nests in the roof structure. A combined treatment with insecticide gel and spot spraying was applied, followed by a preventive intervention three weeks later.

Customer testimonial

"The team was quick and efficient. We thought it was just a seasonal invasion, but it was a full-blown advanced infestation which they mastered in just two visits. They also helped us to identify entry points and correct the damp areas around the house. Excellent service."

Extermination in Longueuil (Vieux-Longueuil sector)

An old duplex in the Vieux-Longueuil underwent an emergency intervention after the discovery of winged ants in the kitchen and bathroom. Inspection revealed a chronic humidity problem in exterior walls caused by clogged gutters and improperly stored firewood.

The treatment was carried out in two phases: application of gel baits indoors, followed by a preventive outdoor spray treatment. The client also received a detailed report with prevention recommendations (sealing, ventilation, garden maintenance).