German cockroaches favor warm, humid spaces near food and water — kitchens, behind appliances, under sinks — and San Luis's one of the hottest climates in the country, tempered only slightly by the river's presence, with summer heat that regularly tops 115°F keeps them active most of the year. American cockroaches, larger and reddish-brown, prefer basements, drains, and utility rooms. Slab-on-grade stucco and manufactured homes built for extreme heat, many oriented around riverfront or canal-adjacent recreational communities.
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.