Squirrels chewing on plastic items such as patio furniture, garbage bins, or irrigation systems is a common and often frustrating problem for homeowners. This seemingly strange behavior is not random but is instead a direct result of the squirrel’s fundamental biological needs and the environment they inhabit. The motivation behind gnawing on non-food items like plastic is driven by both a mechanical necessity related to their unique dental structure and the search for specific resources that the plastic may inadvertently hold. Understanding these underlying drives is the first step toward effectively mitigating the damage they cause.
The Biological Necessity of Gnawing
Squirrels are classified as rodents, a group of mammals characterized by their distinct dental feature of continuously growing incisors. These two pairs of chisel-like front teeth, located on the upper and lower jaws, never stop growing throughout the animal’s life. This constant growth rate necessitates that squirrels gnaw relentlessly on hard, abrasive materials simply to wear their incisors down and keep them at a functional length.
If a squirrel were to stop gnawing, its incisors would eventually overgrow, curving inward or outward. This condition, known as malocclusion, prevents the animal from aligning its jaw to eat and ultimately leads to starvation. In their natural habitat, squirrels meet this mechanical need by chewing on materials like bark, nuts, seeds, and hard wood.
Plastic, especially rigid plastics found on garden furniture or PVC pipes, often serves as an accessible substitute that provides the necessary abrasive texture. The texture and accessibility of various plastic items make them a ready-made tool for dental maintenance. Squirrels use the plastic like an emery board to file down their teeth, not for nutrition. This instinctive, survival-driven behavior explains why they chew through items like vinyl siding or plastic vent pipes that offer resistance.
Seeking Essential Resources in Plastic
Beyond the mechanical need to file their teeth, squirrels are sometimes drawn to plastic because it carries traces of resources they actively seek. The plastic surface itself is often not the goal, but rather the nutrient or substance that has adhered to it. This resource-seeking behavior is driven by three primary attractions: mineral content, hydration, and residual scents.
Mineral Content
Many outdoor plastic items, such as patio furniture or gas grill knobs, can become coated with mineral residues that squirrels are seeking. Salt and other minerals, like calcium, are often deficient in a squirrel’s diet, especially during certain seasons. These essential elements can be deposited on plastic from human sweat, fertilizer overspray, or road salt residue carried by wind or paws. The squirrel detects these trace amounts of minerals and chews the plastic to ingest them.
Hydration
Hydration is another significant draw, particularly during dry periods, leading to the chewing of soft plastics like garden hoses or irrigation drip lines. Squirrels may chew through these items to access the water stored within the plastic tubing. This behavior is most common when natural water sources are scarce, transforming a pliable plastic hose into a makeshift water dispenser. The squirrel is attempting to puncture the material to get a drink.
Residual Scents
Residual food smells also act as a powerful attractant, drawing squirrels to plastic containers used for food storage or waste. Plastic garbage bin lids, for example, are frequently gnawed because they retain the scent of discarded food waste. The squirrel chews through the plastic to access the food inside, demonstrating that the plastic is merely an obstacle in the pursuit of a meal. Even a thin layer of grease on a plastic propane hose connected to a grill can trigger this scent-based chewing behavior.
Practical Strategies for Deterrence
Effective deterrence requires addressing both the mechanical need for gnawing and the search for resources by making plastic items unappealing or inaccessible. One of the most effective strategies is to use taste-based repellents on vulnerable plastic surfaces. Products containing denatonium benzoate or capsaicin create an immediate and unpleasant sensation that discourages chewing without causing harm.
To address the mechanical need, homeowners can provide alternative, acceptable chew materials in a designated area away from the house. Pieces of untreated hardwood or pine cones can satisfy the instinct to gnaw and divert attention from plastic fixtures.
For resource-based chewing, eliminate attractants by keeping plastic garbage cans tightly secured and regularly washing them to remove residual food odors. For outdoor items susceptible to mineral attraction, regularly wiping them down can remove salt and fertilizer residues. Items that are repeatedly damaged, like electrical wiring or gas lines, should be protected by replacing the plastic sheathing with metal alternatives, such as galvanized steel or aluminum tubing, which squirrels cannot chew through.