Rodents are defined by their ever-growing set of super-sharp incisor teeth, which they use for a variety of purposes, such as home invasion. For example, rodents have been known to gnaw at the bottom of doors in order to create an opening large enough for them to squeeze through, and both mice and rats can chew through just about any material, including stucco, wood, plaster, and even concrete. Given the inward curve of their incisor teeth, rodents cannot easily gnaw through surfaces that are hard, flat and smooth, but they can use their sharp teeth and claws to chisel into rough surfaces, surfaces with protruding edges, and cracked surfaces. Rats can gain entry into homes through openings as small as ½ of an inch in width, while mice can squeeze through openings as small as ¼ of an inch in width.
The narrow circular gap that surrounds the openings where utility pipes and cables penetrate the exterior walls of homes can be exploited by rodents looking to invade homes. These gaps should be sealed with a durable material that rodents cannot easily damage, such as Portland cement mortar, Concrete Patch, masonry, or metal collars. Exterior doors should fit tightly and the gap between the bottom of doors and flooring should not exceed ¼ of an inch in width. Metal thresholds like steel pipes can be installed along doorway floors to serve as a barrier to prevent rodent entry. Standard door sweeps will provide temporary protection from invasions, but rodents can easily gnaw through most door sweep products. Flashings or metal channels installed on the bottom edge of doors, particularly softwood doors, works well to exclude rodents from homes. In order to prevent Norway rats from invading homes through a crawl space, ¼ inch wire mesh screens can be placed over foundation openings, and these screens can be placed over attic vents to prevent roof rat invasions.
Is your home rodent-proof?