An owner of a townhouse condo located in a residential complex in Verchères, on the South Shore, contacted our team after noticing the persistent presence of small brown ants in her kitchen and living room. Despite several attempts at self-treatment with products purchased in hardware stores, the infestation systematically returned after a few days. The Saint-Lambert sector, neighboring Verchères, experiences similar problems in the spring, especially in condominiums whose shared foundations offer many routes of circulation for insects.
Inspection and understanding of colonial dynamics
The inspection carried out by our technician revealed the presence of odorous ants (Tapinoma sessile), recognizable by the coconut smell they give off when crushed. This species, which is very common in condos and terraced properties, forms super-colonies with multiple breeding queens, which makes it particularly resistant to surface treatments. The ant tracks were traced from the kitchen counter to the wall adjoining the neighboring unit, which indicated a circulation between the two adjoining dwellings. The main nest was located in the insulation of the foundation wall, accessible from the outside through a crack in the brick cladding. Our approach to house ant extermination takes into account these super-colony dynamics to avoid partial treatments that only shift the problem. Coordination with the condominium manager was recommended to treat adjacent units simultaneously.
Treatment protocol for semi-detached condominiums
Indoors, non-repellent gel baits were placed along active trails and in identified staging areas: behind the refrigerator, under the sink, in cabinet recesses, and along the party wall. The owner was instructed not to clean these areas with bleach for the duration of the treatment, as disinfectant products destroy trail pheromones and disrupt the collection behavior of the workers, reducing the effectiveness of the baits. Externally, perimeter spraying was performed on the foundation and underpinnings of the unit, targeting the crack in the brick siding. An exterior insect treatment covered the entire perimeter of the condo row, with the agreement of the condominium manager, to reduce the outside pressure on all units.
Building-wide sealing and prevention
Our technician caulked the identified entry points on the treated unit: the crack in the brick cladding was filled with a flexible building sealant, and the spaces around the electrical outlets at the bottom of the walls were sealed with low-expansion expanding foam. Recommendations have been submitted to the condominium manager to extend this preventive work to other units with visible cracks in the foundation. The owner also received practical advice: store sugary foods in airtight jars, regularly clean surfaces under appliances, and report any recurrence of activity early to allow for early follow-up. Proactively managing this type of infestation in condominiums requires a collective approach rather than an individual one. It is important to note that in townhouse complexes, a treated unit may be re-infested if adjacent units do not benefit from the same preventive measures, which underscores the importance of coordination between co-owners and managers.
Monitoring and termination of infestation
Two follow-up visits were made at two and four weeks after the initial treatment. The ants’ activity had significantly decreased by the first monitoring visit, and no active leads were visible by the second visit. The owner confirmed that she no longer observes ants in her unit. For other examples of similar achievements, see our house ant construction in a comparable residential context and our intervention against carpenter ants in the South Shore. Nova Extermination intervenes in all types of properties on the South Shore, from single-family residences to condominiums, with methods adapted to each situation.