The Boxelder Bug is a black or dark brown color with red wing veins showing on the abdomen. The nymphs can be all bright red, with a hint of black. They will sometimes be confused with stink bugs. When disturbed, they do have the capability to release a compound that is bad tasting and pungent. This insect is usually found on boxelder trees, but they have been known to be found on ash trees and maple trees. The Boxelder Bug is a pest that primarily invades homes in the fall when the temperature starts to change. There could be hundreds that invade the outside of your home, clumping on the siding, shutters, foundations, and window frames. Eventually, they make their way indoors. Treating the exterior will control them, but doing it preventatively will most likely not be effective. You need to treat when the masses congregate.