How to deal with a carpenter ant infestation in Quebec? Complete guide 2025

Introduction

Carpenter ants are a very problematic pest in Quebec, as they attack the wooden structures of homes, causing significant damage over time. Eliminating them requires a methodical approach that complies with the strict rules governing the use of pesticides since 2023 and especially in 2025, under Quebec's Pesticide Management Code.

Identifying the presence of carpenter ants

Carpenter ants are larger than common ants, with black or brown bodies and wings that are only present on queens and males during the breeding season. Signs of infestation include:

The presence of fine sawdust (wood debris) near foundations, windows, or doors.

Visible tunnels in damp or damaged wood.

The appearance of workers and nymphs, mainly in spring and summer.

An accurate diagnosis is essential and is often carried out by a certified pest control expert.

Current pesticide regulations in Quebec

Since July 6, 2025, Quebec has tightened restrictions on the use of pesticides in residential and commercial settings. Many traditional products containing ingredients such as permethrin or pyrethrins are now banned from retail sale, even though they were previously considered for domestic use. These changes are intended to protect public health and the environment.

Professional treatment must therefore comply with these new standards and use products that are registered and can only be applied by certified exterminators with the required permits.

Recommended steps for eliminating carpenter ants

• Thorough inspection

• Identify the exact location of the nest and the extent of the infestation. This may involve checking wood exposed to moisture, crawl spaces, roof structures, and areas that are often damp.

• Eliminate sources of moisture

• Carpenter ants prefer damp wood. Ensuring good ventilation, repairing leaks, and eliminating excess moisture will limit their development.

• Targeted treatment by a professional

Approved insecticide products must be applied with care to avoid harming the environment and to comply with regulations. A certified exterminator will choose the right products and apply the treatment directly to the nests and infested areas.

Use of complementary methods

The integration of traps, physical barriers, and management of the outdoor environment around the house (wood storage, debris removal) contribute to sustainable control.

Follow-up and prevention

A post-treatment follow-up service is essential to confirm complete elimination and prevent recurrence. Adopt best practices to prevent future infestations: regular monitoring, structural maintenance, and humidity control.

Why choose a certified exterminator?

Only a trained and certified professional in Quebec can legally apply the necessary products in accordance with recently revised standards. They ensure accurate diagnosis, safe treatment, and appropriate follow-up. Failure to comply with pesticide use regulations can result in health risks, administrative penalties, and ineffective treatment.

Conclusion

Managing a carpenter ant infestation in Quebec in 2025 requires a combination of expertise, compliance with regulations, and an integrated approach combining approved chemical methods and preventive measures. Using a certified exterminator guarantees an effective and sustainable intervention, with respect for safety and the environment.