Boxelder bugs are a North American species of true bug that are found primarily on boxelder trees, as well as maple and ash trees. They are about 13 millimeters long with a dark brown or black coloration, relieved by red wing veins and markings on the abdomen; nymphs are bright red. Boxelder bugs are "true bugs" and belong to the same family as stink bugs, cicadas, and other insects with piercing and sucking mouthparts. They feed, lay eggs, and develop on boxelder trees, most commonly occurring on female trees as they produce seeds. Boxelder bugs are not known to cause damage to homes or significant damage to plants, but their feces can stain light-colored surfaces, and smashing them can release an unpleasant odor. They are often found in homes and on the sunny exterior sides of buildings, and during the fall, they can become a nuisance to homeowners as they invade in large numbers. Boxelder bugs are not considered a threat to humans, and they do not sting or transmit disease.