Good sanitation will also reduce food and shelter for existing mice and in turn make the baits and traps more effective. Pay particular attention to eliminating places where mice can find shelter. If they have few places to rest, hide, or build nests and rear young, they cannot survive in large numbers. All places where food is stored, processed, or used should be made mouse-proof. Dried grain and meat products should be stored in glass jars, metal canisters, re-sealable coffee cans, or other air tight containers.
Steel wool mixed with caulking compound makes a good plug.
Patching material needs to be smooth on the surface to prevent mice from pulling out or chewing through the patching compound. Seal cracks and openings in building foundations and openings for water pipes, vents and utilities tightly with metal or concrete. Doors, windows, and screens should fit tightly. It may be necessary to cover the edges with metal to prevent gnawing. Plastic sheeting or screen, wood, rubber, or other gnawable materials are unsuitable for plugging holes used by mice.