The appearance of carpenter ants in a school is a situation that requires particularly careful management, both for the safety of children and for the preservation of an aging wooden structure. In Granby, on the South Shore, an elementary school built in the 1970s reported the presence of ants in several classrooms and in the main hallway, when it returned from summer vacation. The management had observed winged ants in the classrooms and traces of frass in a corner of the library. Our team at Nova Extermination, an extermination specialist in Quebec, responded to the call as a priority, aware of the health issues specific to an environment frequented by young children.
Inspection adapted to the school environment
The diagnosis was planned for a Friday in the late afternoon, after the students had left, to allow full access to the classrooms, gymnasium, cafeteria and technical areas. The inspection focused on areas where structural timber was accessible: old suspended ceilings with wood frames, painted pine window frames, and wood floors in some renovated wings. Active galleries were found in the ceiling joists of the library, in the jambs of a partition adjacent to an old water leak, and in the wooden framing of the northeast-facing secondary entrance. Outside, several old trees with sections of decaying trunk at the edge of the playground served as mother nests. The complexity of the infestation, linked to the age of the building and the presence of multiple historical wetlands, confirmed the need for a structured and documented carpenter ant extermination program.
Treatment protocol adapted to sensitive environments
In an environment frequented by children, the choice of products and treatment methods obeys strict criteria. The selected products had a favourable toxicological profile for humans, with clearly documented drying and waiting times before reoccupying the premises. The interior treatment was based on the injection of insecticidal gel as bait in the galleries and wall voids, a contained method that minimizes the exposure of the occupants. No widespread spraying was carried out in the classrooms or cafeteria. The exterior treatment, carried out at the end of the week, consisted of a direct injection into the contaminated tree trunks and a liquid insecticide barrier at the foundation perimeter. Monitoring traps were set in the treated areas to ensure continuous monitoring. A similar realization in an institutional building is available in our portfolio for reference.
Communication with management and staff
Transparency with the school management and maintenance staff was a priority throughout the intervention. A preliminary inspection report was provided prior to the start of treatment, followed by a full final report with photos. The janitors have been trained on the signs of activity to look out for and the preventive practices to adopt on a daily basis: humidity control, checking window seals after each winter, and quickly reporting any traces of frass. An annual pest prevention plan has been put in place, including a visual inspection each fall and a preventative outdoor treatment in the spring. This type of proactive approach is particularly recommended for older public buildings that are at chronic risk of infestation.
Results and control visit
The follow-up visit, carried out six weeks after the treatment, did not reveal any signs of active activity inside the school. The management has reported a total absence of ants in the classrooms since the resumption of school. The contaminated trees on the site were cut down by municipal services, following the recommendation included in our report. Also consult this case study in carpenter ants and this realization in anthill for other examples of successful interventions in comparable institutional contexts in Granby and its surroundings on the South Shore.