When boxelder bugs are inside a home, attempts at extermination using chemicals are largely ineffective, and the best option is removing them with a broom or vacuum, according to the University of Minnesota Extension. Eliminating access and using insecticides on the outside of the house helps prevent reinfestation.
Preventing these insects from coming into the house requires caulking any cracks that give them access. Replacing damaged window or door screens and the screens over roof and soffit vents is helpful as is caulking any entrances around plumbing, electrical, phone and television cables. In homes with vinyl siding, it is not possible to seal all the openings, but the house wrap under the siding is often effective at keeping out boxelder bugs. Use of chemical pesticide sprays on the outside of the house, regardless of the construction, helps prevent the bugs from entering.
Boxelder bugs have the ability to travel several miles in search of food, so chemically treating trees or removing them from the landscape is ineffective. The bugs also live in maple and ash trees.
These insects do not bite humans and are not a serious problem every year. While the moisture of houseplants sometimes attracts them, they rarely cause damage to the plants. Their excrement sometimes leaves orange stains on the walls or curtains.