İs mothball (naphthalene) harmful to rabbits? I‘ve found butterflies in my rabbits hay and i dumped it.However i still find butterflies time to time in other hays. My mother says we should place mothball in the closet where we keep the hay ( we will move the hay to another place) so it kills the butterflies. We couldn’t think of other solutions beacuse i know insecticides are harmful to rabbits. But maybe mothball is safe ?