Mothballs are a common household item often suggested as a simple solution for pest problems, including the frustrating damage caused by moles. These subterranean mammals create noticeable ridges and volcano-shaped mounds across lawns as they tunnel in search of food. Homeowners frequently attempt to repel these pests by placing mothballs directly into the mole tunnels, relying on the product’s strong, pungent odor to drive the animals away. This popular home remedy, however, fails to account for the chemical nature of the product and the mole’s innate behavior, leading to ineffective results and potential hazards.
Are Mothballs Effective Against Moles?
Mothballs are generally ineffective for achieving long-term mole control and are not approved for this use. While the noxious scent may cause a mole to temporarily abandon a specific section of a tunnel, the animal will not leave the property entirely. Moles are highly mobile and will simply seal off the treated area before digging a new parallel tunnel nearby. The failure of this method lies in the open-air environment of the soil and mole tunnels. The repellent fumes dissipate quickly into the surrounding earth, making it impossible to achieve the concentration needed for a long-term deterrent.
Understanding the Chemical Composition
Mothballs are classified as pesticides and contain high concentrations of either naphthalene or paradichlorobenzene. These solid chemicals are designed to undergo sublimation, meaning they turn directly into a toxic gas or vapor without passing through a liquid state. This vapor is what repels and kills clothes moths and their larvae. The intended use of these chemicals is strictly limited to pest control in confined, airtight spaces, such as sealed storage containers, where the gas can build up to lethal concentrations. When mothballs are placed in soil, however, the toxic vapors immediately escape into the atmosphere and the surrounding earth, preventing them from reaching a concentration high enough to deter a mole.
Health, Environmental, and Legal Safety Concerns
Using mothballs in soil introduces serious toxicity risks to humans, pets, and the environment. Naphthalene and paradichlorobenzene are toxic chemicals; inhaling the vapors can cause headaches, nausea, and irritation to the eyes and respiratory tract. If a pet or child accidentally ingests even one mothball, it can lead to acute poisoning requiring immediate medical attention. Severe exposure to naphthalene can potentially cause a condition called hemolytic anemia.
The improper outdoor use of mothballs also leads to significant environmental contamination. As the chemicals sublimate and dissolve, they leach into the soil, where they can be absorbed by plants and contaminate groundwater sources. This pollution is harmful to beneficial soil organisms, such as earthworms, which are the primary food source of the mole. It can also pose a risk to non-target wildlife.
Mothballs are regulated by the Environmental Protection Agency (EPA), and the product label dictates where and how they can be legally used. Using mothballs for any purpose not explicitly listed on the label, such as for mole control, constitutes a violation of federal law under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). This misuse can result in legal repercussions and is considered a serious public health risk due to the release of toxic substances.
Approved and Effective Mole Control Methods
Effective mole control relies on science-backed methods that either remove the animal or modify its habitat.
Trapping
Trapping is consistently cited as the most reliable and efficient method for eliminating moles. Specialized devices like harpoon or scissors-style traps should be placed in active tunnels to yield the best results. Professional placement of these traps is often necessary to ensure a quick and humane outcome.
Chemical Control
This involves using registered toxic baits, which are formulated to resemble the mole’s natural food source, like earthworms or grubs. These baits must be placed directly into the active tunnel system according to the product’s label instructions to prevent exposure to non-target animals. For a less lethal approach, repellents containing castor oil can be applied to the lawn, as the chemical irritates the mole’s digestive system.
Habitat Modification
Habitat modification can also discourage moles from settling in a yard. Reducing the population of grubs and other soil insects through targeted insecticide application eliminates the mole’s food supply, prompting them to search elsewhere. Installing physical barriers, such as a 24-inch-deep trench lined with wire mesh around garden beds, can also prevent moles from entering vulnerable areas.