Cockroaches need three things to establish a colony: food, water, and warmth. Dorsey's housing stock gives them exactly that. A mix of historic river-town homes, farmhouses, and government-corridor housing around Springfield, most with basements. Combined with Dorsey's climate — a climate that behaves more like the upper South than northern Illinois, with shorter, milder winters — indoor cockroach pressure rarely lets up on its own.
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.