German cockroaches favor warm, humid spaces near food and water — kitchens, behind appliances, under sinks — and Canadensis's a humid continental climate with cold, snowy winters and warm, humid summers, colder than Philadelphia to the south keeps them active most of the year. American cockroaches, larger and reddish-brown, prefer basements, drains, and utility rooms. Housing spans century-old coal-region construction to newer subdivisions throughout the Lehigh Valley.
Treatment starts with locating the harborage points — the tight, warm, food-adjacent spaces roaches actually live in — and applying gel bait directly there rather than spraying open floor space. This targets the colony at its source and avoids the resistance issues that plague over-the-counter sprays. We follow up to verify the population has collapsed, not just scattered.