The presence of squirrels in gardens, fruit trees, and attics can quickly lead to property damage and lost harvests. Homeowners often look for simple, accessible exclusion methods, which frequently leads to the consideration of standard bird netting. This polyethylene or polypropylene mesh is readily available and seems like a straightforward physical barrier. However, bird netting is a solution designed for a different biological problem, and it proves largely ineffective against the determined, persistent rodent. The effectiveness of any barrier against a squirrel depends entirely on its material strength and the structural rigidity of its installation.
Physical Limitations of Standard Bird Netting
Standard bird netting is manufactured from lightweight materials, typically extruded polypropylene or woven nylon, stabilized against ultraviolet (UV) light exposure. This construction is engineered to be a visual and physical deterrent for flying animals. The netting is extremely light, making it easy to drape over plants or structures.
The low tensile strength of the thin plastic or nylon strands is a significant vulnerability. Common bird netting is designed to stop a bird’s flight path, not to resist focused pressure or gnawing. Mesh sizes vary but often range from 3/4 inch to 2 inches, which is suitable for preventing birds from accessing an area. These wide openings are far too large to deter a small, flexible rodent, especially if the material is stretched or loosely installed. The inherent flexibility and lack of rigidity in the material mean it bends and collapses easily upon contact.
How Squirrels Defeat Lightweight Exclusion
Squirrels are highly adapted rodents whose physical needs and behaviors make them uniquely equipped to defeat lightweight barriers like bird netting. Their incisor teeth grow continuously throughout their lives, requiring constant gnawing to keep them filed down and at a manageable length. This biological necessity means they treat any perceived obstacle as an object to be chewed through, not simply avoided.
The soft, pliable nature of plastic or nylon netting provides little resistance to these powerful, sharp incisors. A squirrel can easily chew through the thin strands in a matter of minutes to gain access to a desirable food source. Their remarkable dexterity allows them to use their paws to pull, manipulate, and bunch up the netting. Once bunched, they can create a tight spot to bite through or simply push the material aside to create a pathway for entry. Since squirrels can fit through surprisingly small openings, any tear or loose section of the netting instantly becomes an entry point.
Specialized Materials for Effective Squirrel Exclusion
Effective squirrel exclusion requires a barrier that is both gnaw-proof and structurally rigid. The most reliable material for this purpose is galvanized or stainless steel hardware cloth, which is a woven or welded metal mesh. This material is vastly superior to thin plastic netting because the metal is impossible for a squirrel to chew through.
For squirrel exclusion, hardware cloth with a small mesh size, specifically 1/4-inch by 1/4-inch or 1/2-inch by 1/2-inch, is recommended. Mesh larger than 1/2 inch may allow smaller or juvenile squirrels to squeeze through the opening. The wire’s thickness is also a factor, with a lower gauge number indicating a thicker, stronger wire; 16- or 19-gauge wire is suitable for resisting a squirrel’s attempts to pull or bend the barrier.
Proper installation is as important as the material selection itself. The hardware cloth must be tightly secured to the structure using screws and fender washers to prevent the squirrel from pulling it away from the surface. When protecting areas at ground level, such as a garden bed or a foundation, the mesh must be buried at least 12 inches deep in an L-shape extension, which discourages digging animals from simply burrowing underneath the barrier. For overhead exclusion, like protecting a fruit tree, a rigid frame must be constructed to support the hardware cloth, ensuring the mesh is taut and not draped in a way that allows the squirrel to gain leverage.
Non-Physical Methods for Squirrel Deterrence
While physical exclusion provides the most permanent solution, non-physical methods can be used to discourage squirrel presence. One highly effective technique involves the use of capsaicin, the compound that gives chili peppers their heat. Birds cannot taste capsaicin, but mammals, including squirrels, find the taste and sensation highly aversive, making it useful for treating birdseed or plants.
Scent-based deterrents, such as peppermint oil or strong-smelling spices, can also be applied to surfaces, as squirrels are sensitive to strong odors. Habitat modification is another practical step, involving the removal of known food sources like fallen nuts or fruit and securing garbage bins. Trimming tree branches that hang within eight to ten feet of a roof or power line removes the common aerial pathways squirrels use to access a home’s exterior.