Boxelder bugs are black with bright red or orange lines on their backs. They gather in large groups on sunny walls, doors, and windows in the fall, then try to slip inside through tiny gaps to overwinter. Inside, they show up around window sills, light fixtures, and warm upper levels.

They do not bite or carry disease, but hundreds of them in the house is stressful and messy. They leave stains and droppings on walls and curtains. BRD focuses on exterior treatments before and during peak activity, plus sealing recommendations, so your home does not become their winter cabin.