The abundance and activity of brown marmorated stink bugs, Halyomorpha halys Stål, over-wintering inside a Maryland home were documented. Brown marmorated stink bugs, an invasive species, were collected daily, and their collection rate assessed with respect to outside temperature, location within the structure, and date. During the 181-day study period 26,205 adult brown marmorated stink bugs were collected inside the home. The exiting of stink bugs from hiding in the walls and other suitable areas into indoor living space was positively correlated with outside daily high temperature variation from the long-term daily high. Control measures to block exit from walls into living space reduced collection rate, but failed to halt it. This heavy infestation in a single home demonstrates the potential nuisance to millions of homes across the country if the range and population of the brown marmorated stink bug continues to expand.