"Just throw some mothballs around the foundation" is the most-repeated piece of snake advice in the Southeast. It is also wrong on two fronts: the science does not support it, and using mothballs as an outdoor pest deterrent is illegal under the product's EPA registration.
What mothballs actually are
Mothballs are pesticide. The active ingredient is either naphthalene or paradichlorobenzene. The EPA-approved label restricts use to enclosed spaces — closets, storage trunks, sealed containers — where the fumes accumulate at a concentration that kills clothes moths. Using them outdoors, around a foundation, or in a crawlspace is an off-label application and a violation of federal pesticide law.
Why they do not repel snakes
Snakes do not interpret smell the way mammals do. They flick their tongue to pick up chemical information about prey and other snakes; they do not "avoid" smells the way a deer avoids predator urine. Multiple wildlife studies — including controlled enclosure work — have shown snakes will move directly over mothballs, sometimes resting against them, with no measurable behavioral change.
The harm side
Naphthalene fumes are a documented hazard to children and pets, particularly through inhalation. Children have been poisoned by ingesting mothballs that look like candy. Crawlspaces and garages "treated" with mothballs vent into living space through utility penetrations and HVAC return paths.
What actually works
Snakes follow food and find shelter. Sealing entry points, controlling the rodent population, and removing harborage (leaf piles, woodpiles, dense ground cover near the foundation) is the only durable approach. Our snake biology, signs, and prevention guide walks through it in detail for North Alabama homes.
If you are dealing with active sightings, we run snake calls regularly across the region — see our snake removal service overview for what an inspection covers.
The other myths worth deleting
"Sulfur powder around the house" — same result as mothballs. "Cinnamon and clove oil" — no effect. "Ultrasonic snake repellers" — no peer-reviewed evidence of efficacy. "A clean yard" alone — helpful, but only addresses harborage, not entry. None of these substitute for finding and sealing the gap a snake is actually using.
