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A snake rests in the grass. While some people try to deter snakes using mothballs, experts say the method is ineffective — and illegal if used outdoors.
As snakes emerge from their habitats due to warm weather, many residents begin looking for ways to keep them out of yards, garages and gardens. One common suggestion found in Facebook groups, neighborhood forums and word-of-mouth advice is to crush mothballs and scatter them outdoors to deter snakes.
We found many claims that mothballs are a cheap, easy snake repellent. We can verify mothballs are not proven to repel snakes — and using them outdoors in this way is a violation of federal pesticide law.
What are mothballs made of?
Mothballs contain either naphthalene or paradichlorobenzene, both classified as pesticides by the U.S. Environmental Protection Agency. These chemicals are intended for indoor use only, typically in sealed containers to protect stored clothing. They work by turning into a toxic vapor, which kills insects like moths — but that vapor does not repel snakes.
Do they actually work on snakes?
There is no scientific evidence that mothballs are effective snake repellents. Snakes use a different sensory system than insects. They rely on their tongues and a specialized organ called the Jacobson’s organ to detect chemical cues. Mothball fumes don’t affect this process in a way that would repel them.
The National Pesticide Information Center also warns against relying on mothballs for wildlife control, including snakes.
Is it legal to use mothballs outside?
No. Mothballs are registered as pesticides, and their use is regulated by federal law under the Federal Insecticide, Fungicide, and Rodenticide Act, or FIFRA. Labels clearly state that the product is for indoor use only and is not intended to control snakes or other wildlife.
Using mothballs in any way not specified on the label is a violation of federal law.
Misuse of mothballs can lead to environmental contamination and risks to children, pets and wildlife. Violations can result in warnings, fines or other enforcement actions. In Mississippi, the state Department of Agriculture and Commerce enforces pesticide regulations.
What actually helps keep snakes away?
Pest control professionals and wildlife experts recommend habitat management, not repellents, as the most reliable method of preventing snake encounters. There is no quick chemical fix, but there are proven steps homeowners can take to make their property less inviting to snakes:
— Keep grass trimmed and vegetation low.
— Remove debris piles, wood stacks and dense brush.
— Seal cracks and holes in foundations, sheds and outbuildings.
— Avoid leaving out birdseed or pet food, which can attract rodents and, in turn, snakes.
The bottom line
Mothballs don’t repel snakes — and using them outdoors is against the law. The best way to keep snakes away is to reduce hiding places and food sources on your property. Relying on misinformation could put your health, pets and environment at risk.
The “What Is True?” media literacy initiative, a key function of the Roy Howard Community Journalism Center, is dedicated to investigating false and misleading information. Our team fact-checks claims, provides context and helps the public navigate today’s complex news landscape. Submit your claim at rhcjcnews.com/witreq.