Cockroaches need three things to establish a colony: food, water, and warmth. Tualatin's housing stock gives them exactly that. A mix of older wood-frame homes and newer suburban construction, most without air conditioning given the historically mild summers, and prone to moisture issues given the rain. Combined with Tualatin's climate — a temperate marine-influenced climate with heavy winter rainfall and comfortable, mild summers — 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.