Signs of Infestation
Boxelders bug infestations typically occur in most buildings in the fall, when they’re looking for a place to survive the winter. Depending on the ease of access, you may notice up to hundreds of boxelders in or near your building. Look for swarms of boxelders around windows, particularly windows with western or southern exposure.
Boxelders produce liquid feces, which may stain carpet, rugs, or other fabrics. These stains are small and appear faded yellow, brown, or grey in color. Boxelders may also stain nearby surfaces when crushed. Stains are most noticeable near areas where they congregate like windowsills and door frames.