Boxelder bugs are nuisance pests. They do not sting or transmit disease, and are generally not known to bite, though there are rare reports of defensive biting. Boxelder bugs are not known to cause damage to homes or significant damage to plants. However, their feces can stain light colored surfaces. Smashing them can also release an unpleasant odor.
They are often found in homes and on the sunny exterior sides of buildings. During the spring and summer, boxelder bugs feed and reproduce on female (seed-bearing) box elder trees. Occasionally, they may also feed on male box elder, maple, ash, and some fruit trees. This can sometimes result in minor deformities in fruits and leaves or yellow leaf discoloration. As winter approaches, boxelder bugs seek out shelter from the cold. They can fly up to two miles to find a suitable location in tree stumps, under debris, or within homes. There they remain mostly inactive until the early spring when temperatures begin to rise.