Boxelder Bugs are very common, particulary in rural areas. They're most abundant in early fall, especially after a warm spring and a very dry summer. Boxelders are hibernating insects that seek shelter in attics and wall voids during the winter. Then, the following spring, they can be seen emerging from hibernation sites, and flying to a host tree or gathering on the sides of buildings again.

Boxelders are usually about ½ inch long, and distinct red & black in appearance. They congregate on trees, around rocks, and are attracted to the sunny [south] sides of buildings. From there they get inside through small cracks & crevices in the foundation, around doors and windows, or any other openings they can find.

Boxelder Bugs often become a real nuisance to homeowners and they're difficult to control. Effective control usually requires professional help, including periodic perimeter "barrier" treatments around the exterior to ward them off.