A four-unit apartment building located in Saint-Marc-sur-Richelieu, a rural village in the Montérégie region on the west bank of the Richelieu River, called on our services over the summer after the manager observed several groundhog burrows under the rear gallery and along the foundations. The presence of these rodents was causing increasing nuisance for residents, particularly because of the galleries that weakened the landscaped flower beds and partially destabilized the concrete of the rear parking curb. The excavated area under the gallery already posed a risk of collapse of the wood planks, and two of the structure’s load-bearing columns were showing signs of movement. In the surrounding area, on the Beloeil side, other multi-family properties had already experienced similar problems, testifying to a continuous pressure from marmots in heritage areas bordered by agricultural land.
Initial assessment and mapping of burrows
Our certified technician carried out a detailed inspection of the perimeter of the building in the morning, when groundhog activity is most observable. A total of four active openings have been identified: two under the wooden rear gallery, one at the foot of the east foundation wall, and a fourth hidden under a dense shrub on the façade. The estimated depth of the main galleries exceeded one metre, which is typical of the summer facilities of the common marmot in Quebec. Photos and a scale sketch were produced to plan the intervention effectively and communicate the results to the owner. Our team in Saint-Marc-sur-Richelieu also noted damage to the underground irrigation wiring located near the front burrow, likely caused by repeated excavations of the animal over the weeks. This type of indirect damage is common and highlights the importance of intervening quickly at the first signs of an installation. Our specialist in groundhog extermination in buildings confirmed that several of the galleries ran directly along the underground pipes, thus increasing the risk of damage to the infrastructure. With Nova Extermination, a certified exterminator in Quebec, each mandate begins with rigorous documentation of the situation before the start of the work.
Trap deployment and intensive monitoring
Four cage traps were installed simultaneously on the identified openings, with baits composed of fresh vegetables and sweet fruits renewed daily to maintain a strong attractiveness. Given the number of active burrows and the presence of residents in the building, our team conducted inspection rounds twice a day, making sure to limit inconvenience for tenants. In five days of operation, three adult marmots were captured and relocated to a wooded area located at a good distance from inhabited areas, in accordance with the rules in force. Nova Extermination’s animal capture and relocation protocol meets provincial standards and ensures humane treatment for animals. The fourth opening, which remained inactive for two consecutive days, turned out to be a flight burrow that was probably abandoned following the disturbances caused by our presence on the premises.
Sealing work and preventive management advice
After the capture, our technicians carried out a complete job of closing the entry points. Each burrow was filled with a mixture of crushed stone and well-compacted soil, then sealed with a two-centimetre galvanised mesh mesh, anchored thirty centimetres deep and folded in an L-shape to block any further digging. Sections of geotextile fabric were laid against the foundation to discourage future access to the soft ground around the posts. The technician identified the damaged irrigation wiring so that the homeowner could schedule it to be repaired by an irrigation professional. The manager was informed of the importance of keeping the area around the building clear, not leaving organic matter accessible and regularly monitoring risk areas at the beginning of the season. For more examples of comparable interventions, see our marmot capture in other cities on the South Shore. The combination of complete capture and rigorous sealing ensures that the building will remain protected over the following seasons.