Mothballs – Ditch the Wives’ Tale

by | Sep 29, 2022

With the warm weather of summer, you may have seen a few extra critters around your yard, and that may have brought back up some bad advice on how to deal with them – especially snakes. Even for wildlife lovers, snakes are not always welcomed with open arms, but contrary to pervasive wives’ tales, mothballs shouldn’t be put out in the open to keep away snakes, general insects or other wildlife. Mothballs are intended to be put in closed containers (where vapors don’t easily escape) to keep away one thing – moths. Using mothballs in a way not specified by the label is not only illegal, but can harm people, pets, or the environment.

Source: National Pesticide Information Center

“When you put mothballs out in the open to repel snakes or something else, pets, wildlife, and kids – neighborhood kids or your own kids – can easily get to them. Very often mothballs look like little pieces of candy. Some of them are very brightly colored,” said Beth Dittman, an environmental toxicologist for the NCDA&CS Structural Pest Control and Pesticides Division. “It only takes ingesting one mothball to poison a kid or pet, and so it’s a big concern.”

Year after year, the division receives numerous calls about the misuse of mothballs.

“If pets or kids get their hands on these mothballs, they can be incredibly toxic. People aren’t aware of the dangers,” Dittman said. “Even in local Facebook groups, people will say ‘I have snakes in my yard. What do I do about it?’ and inevitably someone suggests mothballs. While in most cases someone else will reply saying not to use mothballs because they are dangerous and illegal to use outdoors, misinformation is out there.”

If you want to rid your yard of snakes or other pests, look for products that are labeled and approved for outdoor use, contact your local N.C. Cooperative Extension Service to discuss potential steps for pest control, and keep your yard clear of clutter that may provide a suitable habitat for snakes.

Mothballs commonly are made from two pesticide active ingredients – naphthalene and paradichlorobenzene. Naphthalene is commercially used in repellent and insecticide products and can be found in nature when things burn, for example in cigarette smoke, car exhaust and forest fire smoke. Paradichlorobenzene is used as an insecticide and is also included in odor reduction products like urinal cakes and trash can deodorant blocks.

“In addition to being toxic if eaten, mothballs are a fumigant that produce a nuisance odor and are constantly releasing gases,” Dittman said. “So if you use mothballs in the traditional way, when you open up that container where you stored your clothes, you want to do it in a space that’s really well ventilated because you don’t want to be breathing in those fumes yourself.”

Source: National Pesticide Information Center

Just as with any other pesticide, “the label is the law” Dittman explained. In North Carolina, it is a violation of pesticide laws and regulations to violate a pesticide’s label. The label found on the outside of a mothball product’s packaging not only provides instructions for use and discusses hazards if the product is inhaled or swallowed, but also has statements like, ‘Do not place in areas accessible to children’. Statements like these are enforced by the NCDA&CS Structural Pest Control and Pesticides Division. So, if you or your neighbor use mothballs outdoors, this would be considered illegal use of a pesticide and the division has grounds to take action.

“It’s important to remember that ‘The Label is the Law’. If someone is using mothballs incorrectly and it creates some sort of risk to human health or environmental health or both, the department can take action against them. It is so important for anybody using any pesticide product to make sure that they’re following the label in terms of how it’s used to reduce risks to human and environmental health,” Dittman explained.

If you’re interested in more details about mothball use, plus resources about health effects, chemical properties and regulation, the National Pesticide Information Center compiled a “one-sheet” on the topic that can be found online at

As the Division’s toxicologist, Dittman’s job is to assist the division in answering questions related to the risks of using pesticides. Pesticides are defined as any product or mixture of products intended to kill, repel, deter, or mitigate a pest and includes herbicides, insecticides, fungicides, and so on. Dittman also oversees the division’s programs that work to reduce the risk of environmental releases of pesticides including the Pesticide Disposal Assistance Program and the Agricultural Pesticide Container Recycling Program.