Last spring, a family owner of a single-family residence in Mont-Saint-Hilaire, on the South Shore, called on our team after discovering a colony of black ants invading the kitchen and pantry. The house, located not far from the McMasterville sector, had several cracks in the foundation joints that facilitated insect access to the interior. From the first call, our exterminator in Mont-Saint-Hilaire went to the site to assess the situation and propose an appropriate action plan.
Inspection and identification of the species
The initial inspection confirmed that they were common black ants (Lasius niger), a species that is particularly active in the South Shore regions during the months of May to August. The technician followed the ant trails from the kitchen to their main entry point: a crack in the concrete flashing under the patio door, aggravated by the freeze-thaw cycles typical of the Quebec climate. Further inspection of the outer perimeter revealed two satellite nests in the decorative stone garden borders along the house. The presence of breeding queens in the main nest indicated a well-established colony, which required a thorough treatment rather than a simple surface application. Understanding the biology of the insect is fundamental: house ants follow trail pheromones, and as long as the source is not eliminated, partial treatments only give temporary results. Our approach to house ant extermination is based precisely on this understanding of colonial behavior.
Targeted treatment and colony removal
The treatment protocol consisted of several coordinated steps. Indoors, the technician applied a specialized bait gel in small, discreet deposits along the active tracks, including behind the refrigerator, under the sink, and in the nooks and crannies of the pantry. This type of bait is formulated for the workers to carry to the queen, which ensures the gradual elimination of the entire colony rather than isolated individuals. Outdoors, contact spraying based on registered insecticides was carried out around the foundation perimeter, focusing on the areas where the floor and the house is connected. The satellite nests in the garden borders were treated directly with a dry insecticidal powder injected under the stones. The entire intervention was carried out in compliance with the safety protocols for the occupants and the pets present in the home.
Caulking and sustainable preventive measures
Once the chemical treatment was applied, our technician caulked the entry points identified during the inspection. The crack in the flashing was sealed with a freeze-resistant polyurethane sealant, and the gaps around the pipes running through the foundation were sealed. These mechanical interventions are just as important as chemical treatment: they prevent ants from recolonizing the house through the same accesses. Recommendations were also given to homeowners regarding the management of food attractions: keep dry food in airtight containers, clean kitchen surfaces regularly, and avoid accumulating firewood directly against the walls of the house. These habits significantly reduce the risk of recurrence in the long term.
Monitoring and results
A follow-up visit was performed a few weeks after the initial treatment. The ants’ activity inside had stopped completely, and no new leads were visible. Outside, a few isolated ants were observed on the edge of the property, without any apparent colonial organization, which is normal in a natural environment. The case was closed as resolved after this control visit. For homeowners who want to go further in protecting their home, we also offer an annual pest prevention plan covering several types of insects and rodents. You can consult other similar cases handled in the region, including our house ant realization in a residential area which illustrates our method of working in a single-family environment. Nova Extermination is at your service for any residential or commercial pest problem on the South Shore and South Shore of Quebec.