In the heart of a residential area of Saint-Charles-sur-Richelieu, in the Richelieu Valley in Montérégie, the owners of a single-family home noticed scratching noises in the walls and characteristic droppings in the shed adjoining the garage. Located in this historic and agricultural sector along the river, between Saint-Marc and Saint-Denis, this type of property is particularly vulnerable to intrusions by field mice, especially as fall approaches, when these rodents are looking for a warm refuge to winter. The Nova Extermination team was mandated to assess the extent of the infestation and carry out a complete treatment.
Inspection and identification of the problem
From the first visit, the technician carried out a thorough inspection of the exterior perimeter and accessible interior spaces. The wood mice (Apodemus sylvaticus) leave very specific clues: small faeces about four millimetres long, tunnels in the ground along the foundations, and bite marks on electrical cables in the mechanical room. Our exterminator in Saint-Charles-sur-Richelieu identified at least three entry points under the threshold of the garage’s service door as well as a crack behind the exterior heating panel. The presence of nests composed of sheets and insulating fibres confirmed active colonisation in the crawl space.
This inspection step is fundamental: it allows us to draw up an accurate picture of the infestation before choosing the intervention methods best suited to the configuration of the premises. Without a rigorous diagnosis, a treatment could prove ineffective in the medium term.
Treatment plan and placement of devices
The protocol chosen for this residence in Saint-Charles-sur-Richelieu combined several complementary approaches. First, approved mechanical traps were placed along the detected traffic corridors, particularly in the crawl space, behind the garage workbench and along the walls of the shed. Secure bait stations, inaccessible to pets and children, have been installed outside at crossing points frequented by field mice. These stations contain second-generation rodenticides, the use of which is governed by the Quebec regulations in force.
At the same time, caulking work on the entry points was carried out: sealing of foundation cracks with hydraulic mortar, installation of metal plates on defective door sills and application of expanding polyurethane foam to the pipe passages. These exclusion interventions are essential to prevent new individuals from settling once the field mice present have been eliminated. To learn more about the services available in the area, visit our page dedicated to field mouse extermination.
Monitoring and results obtained
Two follow-up visits were scheduled in the weeks following the initial treatment. During the first visit, the mechanical traps had captured several individuals, confirming the residual activity in the crawl space. The bait stations showed signs of consumption, indicating that the field mice still present were feeding there. On the second visit, no new activity was detected and all devices were removed or secured. The owners received a comprehensive report and recommendations to maintain the long-term outcome, including removing the piles of firewood against the foundation and managing bird feeders that were a food source for rodents.
This type of intervention is a good example of the holistic approach taken by our team: active treatment, physical exclusion and sustainable prevention. For similar cases solved in other areas of the Richelieu Valley, you can consult our achievements on recent field mouse interventions and on comparable mouse treatments.
Long-Term Prevention for Homes in Saint-Charles-sur-Richelieu
The residential neighbourhoods of Saint-Charles-sur-Richelieu, particularly those bordering the farmland along the Richelieu River, are exposed every year to migratory waves of field mice in the fall. To reduce the risk of a new infestation, we recommend maintaining a clear strip of at least one metre around the foundation, cutting tall grass and limiting the deposit of organic matter such as dead leaves or poorly closed compost. A prevention plan adapted to the properties of the region is available from our team and is the best investment to avoid a return of field mice the following season.