The essentials
Because the first cold nights send them looking for heated shelter, and a gap of about 6 mm is enough to get in. Rodent control removes the mice already inside; if the gaps stay open, others take the same route the next year. A lasting result combines elimination with sealing the entry points using materials mice cannot gnaw through.
It is a familiar pattern: a quiet house all summer, then scurrying in the ceiling void as soon as October arrives. They are not necessarily the same mice, but rather their neighbours from the garden, the cellar or next door, who found the same way in.
Entry points nobody notices
During the Locate stage, the technician follows the signs (droppings, greasy rub marks, gnawing) back to where the mice get in. It is nearly always the same places:
- Pipe penetrations behind the sink, washing machine or boiler.
- Cable conduits and service risers between floors.
- Garage, cellar or utility room doors with no seal at the bottom.
- Damaged air vents and roller-shutter boxes.
- Loose skirting boards and wall linings open onto a service void.
Sealing with the right materials
A mouse gets through expanding foam and silicone with ease. We use steel wool or fine mesh set in mortar or sealant, collars around pipes, brush door strips and metal vent covers.
Order matters: gaps are sealed once the mice inside are gone, otherwise they end up shut in. This is part of the Prevent stage of the Repère Protocol.
Plan ahead
Late summer is the right time for an inspection: entry points are found and sealed before the cold. For a shop, a building or a storage unit, a vigilance contract includes regular visits to the sensitive spots all year round.
Remember
- About 6 mm is enough for a mouse to get in.
- Pipes and ducts are the most common entry points.
- Steel wool, mesh and mortar: foam alone won't hold.
- A late-summer inspection prepares for autumn.
General information, valid at the date of publication; it is no substitute for advice from a lawyer or a health professional.