Rats are a pervasive nuisance for homeowners, often seeking shelter, food, and warmth inside structures. Their presence can lead to significant property damage and potential health risks. Wire mesh is a common material used to prevent these rodents from entering buildings, but a frequent question arises: can rats chew through it? This analysis will explore the biological capabilities of rats and the properties of wire mesh to determine its effectiveness as a barrier.
Understanding Rat Chewing Power
Rats possess remarkable chewing capabilities, primarily due to their continuously growing incisors. These two pairs of chisel-like front teeth, one in the upper jaw and one in the lower, grow throughout the rat’s life, with some rat incisors growing as much as 1 millimeter daily if unopposed. This continuous growth necessitates constant gnawing to keep the teeth at a manageable length and prevent overgrowth, which could lead to severe oral health issues and hinder their ability to eat.
The hardness of a rat’s tooth enamel contributes significantly to its destructive potential. Rat teeth rank approximately 5.5 on the Mohs scale of mineral hardness, making them harder than iron and copper, and even harder than human tooth enamel, which ranks around 5. This hardness, combined with a powerful bite force, allows rats to gnaw through a surprising array of materials. A rat’s jaw muscles can exert a bite force considerably higher than a human’s, which is approximately 160 PSI. This combination of perpetually growing, hard teeth and strong jaws makes rats formidable chewers, enabling them to compromise many common building materials.
Assessing Wire Mesh Vulnerability
The effectiveness of wire mesh against rat chewing depends heavily on its material, wire gauge (thickness), and mesh opening size. Rats can chew through softer metals like aluminum, lead, and copper. Copper mesh, while resistant to corrosion, is softer than stainless steel. Harder metals like steel, especially hardened steel and certain metal alloys, are too tough for rats to penetrate.
Wire gauge refers to the thickness of the individual wires; a lower gauge number indicates a thicker wire, providing greater resistance to gnawing. For effective rat exclusion, mesh with a sufficiently thick wire is necessary. The size of the mesh openings is also a factor; rats can squeeze through surprisingly small spaces, able to flatten their bodies and pass through openings as small as 1/2 inch (approximately the diameter of a thumb). Mesh with openings larger than this can easily be breached.
Selecting and Using Effective Mesh
For effective rat exclusion, specific types of wire mesh are highly recommended. Hardware cloth, made from galvanized or stainless steel, is a preferred choice due to its strength and durability. Stainless steel mesh offers superior corrosion resistance and is robust enough to withstand gnawing attempts, providing a long-lasting barrier. Galvanized steel mesh, which is steel dipped in molten zinc for a protective coating, also offers good durability and corrosion resistance, with a lifespan of up to 20 years.
When selecting mesh, a wire gauge of 19 or lower (meaning thicker wire) is recommended for rat control. Mesh opening sizes should be 1/2 inch or smaller to prevent rats from squeezing through. Some sources suggest even finer mesh, such as 1/4 inch or 6mm (approximately 0.25 inches), as ideal for preventing rats and mice from entering. For comprehensive protection against smaller pests like mice, a mesh with openings no larger than 6mm x 6mm is advised.
Proper installation is as important as the mesh type itself. The mesh should be securely attached to the surface, leaving no gaps or openings that rats could exploit. Using screws, staples, or strong adhesive to firmly secure the mesh is essential. Overlapping edges and sealing around the mesh with caulk or sealant can further enhance its effectiveness. For areas prone to rodent activity, such as around pipes, vents, or foundation cracks, a tightly packed barrier of appropriate wire mesh is a reliable solution.