In southern states, the females begin egg laying n late April, but they do not start until late May or early June in the northern states. Outside, the fecal material from both the adults and larvae can spot car finishes, especially on hot summer days.
It is the adults of the last generation which often enter structures to overwinter. They may overwinter under siding, in wall and/or ceiling voids, attics, chimneys, and ventilators, behind curtains, drapes, and pictures, under carpets, between books, and in other protected places. Inside they are a nuisance pest, and will leave stains if crushed.