Managing a carpenter ant infestation in an apartment building is a challenge of much greater complexity than that of a single-family home. In Saint-Marc-sur-Richelieu, on the South Shore, a six-unit building located in a residential area developed since the 1990s, near the neighbourhoods of Sainte-Julie, was affected by a large colony that had gradually colonized the building’s wood frame. The owner had first noticed winged ants in the common corridor in the spring, a characteristic sign of a swarm indicating a mature colony ready to reproduce. Our team of exterminators in Saint-Marc-sur-Richelieu took care of all diagnostic and treatment operations.
Multi-housing diagnosis and mapping of infestation hotspots
Inspecting a rental property requires coordination with each tenant and a systematic room-by-room approach. The technician first inspected the common areas, the common cellar, the risers and the exterior door frames. Active galleries have been located in the joists of the ceiling of the ground floor as well as in the frame of a north-facing window on the second floor, an area often subject to water infiltration. The characteristic frass, composed of fine chips and insect debris, was found in two separate dwellings, confirming the presence of multiple satellite nests within the structure. Outside, a dead tree near the main entrance and two decomposed wooden poles at the edge of the parking lot were the presumed mother nests. The mapping of the infestation made it possible to establish a precise treatment plan, by zone and by level.
Coordinated treatment in a rental setting
The carpenter ant extermination program in a rental building requires rigorous preparation to minimize inconvenience to the occupants. After prior notification to the tenants, the treatment was carried out on a dwelling-by-dwelling basis over two consecutive days. Injections of slow-transfer insecticidal gel were carried out in the identified wall galleries, supplemented by a spraying of residual insecticide concentrate in the building voids, false ceilings and hollow spaces of the party walls. The exterior treatment consisted of the application of an insecticidal liquid as a perimeter barrier around the foundations and a direct injection into the contaminated poles. The dead tree was the subject of an urgent recommendation to the owner for felling, since its presence constituted a permanent reservoir of colonies. This type of coordinated intervention is documented in this other realization in carpenter ants carried out in a similar context.
Caulking and structural preventive measures
The preventive component of the intervention included professional caulking of the points of entry identified during the inspection. The junctions between the edge joists and the concrete base were treated with a water-repellent sealant, and the openings around the electrical cable and piping entrances were sealed with steel wool and hydraulic cement. The clogged gutters were reported to the owner as a source of moisture contributing to the degradation of the lumber. An annual preventive maintenance plan has been proposed, including a visual inspection of common areas each spring, the period when carpenter ants swarm in Quebec.
Results and results of the operation
The follow-up visit conducted one month after treatment revealed no new activity in the treated dwellings. The owner felled the dead tree identified as the mother nest, which considerably reduced the risk of recurrence. Nova Extermination submitted a complete report with supporting photos, documenting each area treated and the products used. This transparency is particularly important in a rental context where the landlord must be able to demonstrate his or her diligence in terms of maintenance and sanitation. To see other cases treated in the region, check out this anthill project in a comparable residential context.