Box elder bugs are harmless to humans and pets, but their habit of crawling indoors to survive winter weather makes them a significant nuisance for homeowners. Several different methods can be used to get rid of box elder bugs, including destroying their habitat, sealing your house, and spraying the bugs themselves.
The best way to destroy box elder bugs is to remove any female box elder trees near the house. Since box elder bugs breed in box elder trees, removing their habitat will also remove or significantly reduce their population as well. If the trees cannot be removed, have a pest control professional spray the trees with insecticide to kill box elder bugs and their eggs.
Box elder bugs seek shelter in fall, as the weather turns colder. They tend to congregate on the south side of houses, where they use cracks in the sides of the house to slip indoors. The best way to control box elder bugs indoors is to prevent them from getting into the house in the first place. Carefully examine the exterior of the house, especially on the south side, and seal any cracks in the siding or chimneys. Replacing torn screens and caulking window and doorframes can also help keep box elder bugs from getting into the house.
Once box elder bugs are indoors, there are several ways to get rid of them. Since they cannot bite and are not poisonous to children or pets, box elder bugs can be rounded up and either thrown outdoors or squashed. In addition, box elder bugs in the house can be sprayed with pyrethrin-based insecticide or with a solution containing four percent dish soap mixed with water. Read insecticide labels carefully to avoid causing injury or illness to family, pets, or furniture. Both the pyrethrin-based insecticide and the dish soap solution must be sprayed directly on the box elder bugs in order to kill them.