Mothballs are often considered for ant control, especially in outdoor settings like gardens and yards, due to their strong odor. Many people turn to this household item believing its strong odor can deter or eliminate ant populations. However, using mothballs for this purpose introduces significant safety and environmental risks that far outweigh any perceived benefit. This guide clarifies the intended function of mothballs, their limited effect on ants, and the serious dangers associated with their misuse.
Chemical Composition and Intended Use
Mothballs are classified as pesticides, typically containing a high concentration of either naphthalene or paradichlorobenzene (PDCB). These solid chemicals work through a process called sublimation, transforming directly into a toxic gas designed to kill clothes moths and their larvae. The Environmental Protection Agency (EPA) registers these products only for use inside tightly closed, airtight containers to kill fabric pests. This sealed environment allows toxic vapors to accumulate effectively while preventing fumes from escaping into living spaces. Using mothballs in any manner not specified on the product label, such as for general pest control or placing them outdoors, is considered illegal and dangerous “off-label” use.
Efficacy Against Ants
The idea that mothballs control ants stems from their pungent smell, which may temporarily disrupt ant trails. Ants rely heavily on pheromones for communication and navigation, and the strong vapor can mask these chemical signals, causing momentary confusion. However, mothballs are not a reliable or long-term solution for ant infestations. The chemicals are not formulated to penetrate and destroy the ant colony’s deep underground nest structure or eliminate the queen. Their potential to deter a few ants is minimal and short-lived compared to the substantial toxicity risks they introduce to the environment.
Severe Health and Environmental Risks
Scattering mothballs outdoors releases highly toxic vapors into the surrounding air and soil. Naphthalene is classified by the EPA as a persistent, bioaccumulative, and toxic (PBT) chemical, meaning it does not easily break down and can contaminate the soil and groundwater. The toxic vapors pose a serious inhalation hazard to humans and pets. Acute exposure can cause headaches, nausea, vomiting, and dizziness. Ingesting mothballs, which children and pets may mistakenly do, can lead to much more severe poisoning, including damage to red blood cells and hemolytic anemia.
Safe and Approved Ant Control Methods
Effective and safe ant control focuses on eliminating the colony at its source without introducing dangerous chemicals into the environment. The most reliable method involves using ant baits, which contain a slow-acting poison mixed with an attractive food source like sugar or protein. Worker ants carry this toxic bait back to the nest, sharing it with the queen and the rest of the colony, leading to its eventual elimination. Other effective strategies include using food-grade diatomaceous earth, a natural powder that kills ants by dehydrating their exoskeletons. Sealing all cracks and gaps around the home’s foundation, doors, and windows is a proactive step that prevents entry, and these approved methods mitigate risk to people, pets, and the broader ecosystem.