Home owners with a frog or toad problem are often desperate to rid themselves of the evening singers and croakers. In trying to find a solution, some have turned to using strategically placed mothballs in the home and yard. While mothballs have been found to repel frogs and toads, using them in this way is illegal and may do more harm to humans, animals and the environment than the frogs and toads do.

Frogs prefer to live in damp areas or places near water.

Mothball's Active Ingredients

Mothballs are small, crystal white balls that look innocuous but have lethal effects on fabric pests. They are made from high concentrations of either naphthalene or paradichlorobenzene. These two chemicals slowly change from a solid into a toxic vapor, giving mothballs their distinctive odor. They are intended for use in a closed area, such as a plastic storage bin where you keep your clothes, not in the open. Keeping mothballs confined traps the fumigant and limits human and animal exposure and inhalation. Mothballs are regulated by the Environmental Protection Agency (EPA) and labeled for use as an insecticide. Because of this, using them for a purpose other than to destroy fabric pests is illegal.

Health Concerns

Mothballs placed anywhere in the home or yard become a safety issue, especially for children and animals (including pets) who may ingest them or inhale the vapor. Nausea, vomiting, headaches and dizziness have been reported from exposure to both naphthalene and paradichlorobenzene mothballs, which also can irritate skin, eyes and nasal passages. Naphthalene, whether ingested or inhaled by humans or animals, causes damage to the red blood cells in the body, resulting in hemolytic anemia. Once in the body, paradichlorobenzene breaks down into other chemicals that can cause cellular and organ damage. Paradichlorobenzene has also been found to pass through breast milk.

Environmental Dangers

When placed in the environment to deter frogs and toads, mothballs often melt, allowing the chemicals to contaminate soil and leech into groundwater and other waterways. If placed in a garden or yard, the chemicals in mothballs can bind to elements in the soil and be absorbed by growing plants in your garden. Mothballs placed near water will end up in the water. If you have a pond on your property, fish and other wildlife will be affected by the chemicals.

Other Ways to Deter Frogs

Frogs and toads are natural predators of many garden pests. Having a small population in your yard or garden will keep the number of insects, including mosquitoes, under control. If your frogs or toads become too numerous, try more practical methods to encourage some to relocate.

Frogs need water to lay their eggs. If there's standing water on your property, putting a drainage system in place may help. If you have a pond and treasure its fish, surround the pond with fine netting to keep the frogs from accessing the water to lay eggs or to feed on small fish.

If possible, keep outdoor lights off at night. Insects attracted to light will in turn attract frogs looking to feed.

Frogs need damp places to live in, so keep any vegetation surrounding your home trimmed, especially trees that could provide access to your gutter and roof, to deter frogs from moving in.

If all else fails, round up the amphibians and physically remove them from your property.