Rodent-Proof Construction - Structural

Introduction
Rats and mice cause serious damage to homes, farm buildings and feed storage structures. One rat can eat about 30 pounds of grain per year and will contaminate perhaps 10 times that amount with their urine, feces, and hair. Contamination reduces the market value of stored grain and the palatability of feed for livestock. Rodents destroy insulation and other structural components of buildings. Damage to insulation alone may amount to several thousand dollars in only a few years (Figure 1). Energy loss from rodent-damaged buildings results in added annual costs. Rodents also spread a variety of diseases, such as brucellosis, leptospirosis, salmonellosis, swine dysentery, toxoplasmosis, trichinosis, and tuberculosis to livestock and humans.

Rodent-proof construction is the first and most important step in reducing rodent damage. Techniques discussed here apply to new construction and to modifying existing buildings. Rodent-proofing is a good investment. It is less expensive to design and build a rodent-proof structure than to add rodent-proofing later. Additional methods to consider in an integrated pest management (IPM) program include sanitation, toxicants, and trapping.

To prevent rodent entry, their capabilities must be understood.

A common entry point into agricultural buildings for mice is the unprotected end of metal siding. If not blocked with metal or mortar, these openings provide access into the wall spaces and interior of the building. Rats and mice can quickly gnaw through rubber or vinyl weather stops. Design or modify buildings using metal siding so these openings do not provide access routes.

Gaps or flaws often exist along building exteriors where the wall framing or siding meets the foundation, which provide easy access to rodents.

When rats or mice are present in a building, attention must be given to interior as well as exterior rodent-proofing to remove all sources of shelter. Eliminate hiding places for rodents.