Box elder bugs normally feed on the leaves, flowers, and seed pods of the box elder tree or silver maple. Large numbers of box elder bugs are usually on the female, or pod-bearing, tree. These insects feed on male box elder trees and other trees and plants, but they usually do not build up to such large numbers. The adults search for a place to over winter which brings them into houses where they hide in small cracks and crevices in walls, door and window casings, attics, and around the foundation. During warm days in winter and early spring they come out and scatter through the house. They are primarily a nuisance as they crawl or fly about in the rooms.