Why are carpenter ants so common in Longueuil?
Longueuil combines three factors that make it ideal carpenter ant territory: aging building stock, residual moisture, and mature trees. Here's how they settle in and how to prevent them.
If you live in Longueuil and you've seen fine sawdust near a baseboard or window frame, you're not alone. Carpenter ants (Camponotus pennsylvanicus) are one of the most common structural pests on the South Shore, and Longueuil concentrates several factors that attract them.
An aging building stock
Much of Old Longueuil and the LeMoyne sector dates from before 1970. Wood framing from that era has had time to absorb moisture, develop micro-cracks, and offer carpenter ants the softened wood they prefer. Carpenter ants don't eat wood — they tunnel galleries to nest in.
River-proximity humidity
Longueuil is bordered by the Saint Lawrence River, creating a damper microclimate than inland areas. Humidity accelerates degradation of exposed wood (window frames, soffits, decks) and invites satellite colonies to settle in the structure.
The mature tree canopy
Old maples, elms and oaks in Longueuil residential sectors often host parent colonies. When those colonies overflow or seek to extend their territory, satellite colonies look for neighboring structures. If your branches touch the house, you're literally offering a bridge.
How to tell if you have them
Most reliable signs: small sawdust piles (frass) in mid-summer or early fall, winged ants emerging from interior cracks in spring, cracking sounds at night in a wall, or worker ants (8-12 mm, black to dark brown) on countertops. If you see these signs, act fast — colonies grow by hundreds each month.
Concrete prevention
First, cut any branch touching the house. Second, seal foundation cracks and around windows with quality caulking. Third, identify and immediately repair any moisture source (leak, drainage, blocked gutter). Fourth, keep firewood at least 5 metres from the house.
When to call a professional
If you see more than 5 winged ants inside in 24 hours, if you observe multiple frass piles in different spots, or if you hear activity in a wall, it's time to call. Professional intervention eliminates the parent colony (without which the problem always returns); an optional 30-day follow-up can be scheduled to confirm the result.