In addition to repelling or killing insects such as moths and silverfish, mothballs have been suggested for use as a stovepipe cleaner, a snake repellent, and to keep away mice or other pests. However, a major concern about the use of mothballs as a snake, mouse, or animal repellent or poison is their easy access to children, pets, and beneficial animals. Leaving them in a garden or in a living space unprotected makes it very easy for unintended victims such as children and pets to gain access to them. Mothballs are highly toxic when ingested (they have a sweet odor and taste, making this more likely), and will cause serious illness or death. In addition to this, using a large quantity of mothballs in a basement or a living space may cause serious respiratory problems in people living in the space.
Mothballs have been promoted as a squirrel repellent, and are an ingredient in some commercial repellent products. They are generally ineffective, and are not a substitute for physical measures to exclude squirrels from building interiors.