German cockroaches favor warm, humid spaces near food and water — kitchens, behind appliances, under sinks — and Peoria's one of the hottest urban climates in North America, with triple-digit heat for months at a stretch and winters mild enough that pests rarely fully die back keeps them active most of the year. American cockroaches, larger and reddish-brown, prefer basements, drains, and utility rooms. Predominantly slab-on-grade stucco homes from the 1970s-2010s desert suburban boom, with block-wall backyards and no basements.
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.