German cockroaches favor warm, humid spaces near food and water — kitchens, behind appliances, under sinks — and Dover Afb's a coastal climate milder in winter than northern Delaware, with hot, humid beach-town summers keeps them active most of the year. American cockroaches, larger and reddish-brown, prefer basements, drains, and utility rooms. A mix of beach cottages, newer coastal construction, and farmhouses on the flat Delmarva farmland, many built on crawl spaces given the high water table.
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.