Squirrels will readily take up residence in a building if access to sheltered areas such as eaves and attic crawl spaces is available. Gnawing, scratching, and pattering sounds, in early morning or daylight hours, usually signal their presence. Balls of torn insulation, cardboard, and dried leaves and twigs may pinpoint nests, but nests and young may be totally concealed within eaves or wall spaces. Squirrels in house eaves and attics can damage insulation and electrical wiring and should be removed. When blocking holes to prevent squirrels and other animals from gaining access, be sure that none are trapped inside.
Adults can cause severe damage by chewing to regain entrance to reach their young.
If chewing persists, heavy, half-inch wire mesh can be temporarily placed over the problem area. Trimming shrubs and vines and pruning overhanging tree limbs may discourage squirrels from causing problems in the home. In easily accessible areas, squirrels may be evicted by carefully applying an odor repellent like mothballs. Bright lights or noise from radios may also help. Gray squirrels are highly excitable and can cause severe damage if trapped inside a building.