Stink bugs are about 3/4 inch long with distinctive shield-shaped bodies nearly as wide as they are long. Stink bugs are also called shield bugs. Usually dull brown or gray with two pairs of wings that overlap their backs in the shape of an "X," stink bugs use color as camouflage and may be green or black with red markings.
Stink bugs are named for the foul-smelling liquid they secrete in defense. True insects, stink bugs have sucking mouthparts and feed on plant juices or the fluids of other insects, depending on species. Insect-feeding stink bugs are beneficial, but plant feeders are a serious agricultural pest and can damage garden plants. Attracted to the warm outside walls of buildings, stink bugs overwinter indoors in wall voids, reemerging in spring. On sunny winter days, they may be observed on indoor walls.