The best way to keep buildings rodent-free is to prevent rats and mice from getting inside. Rodents fit through tiny openings and can gnaw through wood, lead, aluminum, copper, cinder block, and uncured concrete. Mice can squeeze through gaps larger than 5/16 inch, and rats can squeeze through gaps larger than 1/2 inch. They will enlarge openings that are too small by gnawing them big enough for their body to fit through. The following measures, with the proper materials, will make buildings less accessible to rodents:
- – Patch openings in walls larger than 1/4 inch using gnaw-proof materials, such as steel sheeting, 1/4 inch hardware cloth, galvanized steel, and concrete. Holes may be plugged with steel wool or copper mesh prior to patching.
- – Seal gaps under siding at the top of the foundation.
- – Seal openings around pipes and conduits where they pass through exterior walls.
- – Close outside doors tightly when not in use.
- – Install tight-fitting weather stripping on the bottom of all pedestrian doors and overhead doors.
- – Cover all air vents with 1/4-inch hardware cloth. Make sure dryer vent “flaps” are working properly.
Eliminating places that may provide rodents with shelter, water, and food is the purpose of sanitation.
- – Eliminate debris in and around buildings and grounds.
- – Trim weeds and brush and keep grass short (3 inches or shorter) to minimize cover and food sources around the building perimeter.
- – Clean up food waste and spillage daily.
- – Store food 12 to 15 inches off the floor and 12 to 18 inches away from the wall for easy inspection and sanitation. Use rodent-proof containers when possible.
- – Allow 24-inch aisles between stored materials and walk for improved sanitation and inspection.
- – Screen dumpster drainage holes with hardware cloth.
- – Don’t leave pet food out overnight. Clean up dog droppings daily.
- – Eliminate water sources available to rodents.
- – Clean up windfall fruits, nuts, and bird feeder spillage daily.