During warmer weather, stink bugs will gather in places that have a lot of sun exposure. Some such places include the sides of buildings and around the outsides of windows and doors. If they find cracks or gaps, they will enter a building. They usually enter when the weather starts to cool down. Once inside, they will spend the winter living under floorboards or in walls, attics, and crawlspaces. For the most part, they will stay hidden until spring.