Why should you not kill cockroaches?

You should not kill cockroaches by squishing or using repellent sprays as your primary method because those methods create hygiene issues, fail to eliminate colonies, and can make infestations worse, though you should kill them using targeted baits that eliminate entire colonies. Squishing German cockroaches and American cockroaches smears bacteria like salmonella and E. coli from their bodies onto surfaces, plus their droppings, shed skins, and body parts contain allergenic proteins that trigger allergies and asthma when crushed and become airborne, creating health risks. Squishing also does not address hidden colonies with hundreds including nymphs and egg cases in wall voids and under appliances, so new roaches quickly replace those killed, and squishing can release alarm pheromones that attract more roaches to investigate. Using repellent sprays that kill on contact causes scattering where surviving roaches move to other areas and form satellite colonies, making infestation spread rather than decrease, and sprays do not reach nests. Additionally, some myths claim squishing spreads eggs, and while German cockroaches carry egg cases with 30 to 40 eggs that could potentially release if crushed mature, main reason not to squish is ineffectiveness and contamination. Instead of not killing at all, you should kill using integrated pest management including thorough sanitation by storing food sealed and cleaning crumbs, sealing cracks with caulk, vacuuming roaches with HEPA vacuum, and using slow-acting gel baits containing fipronil or indoxacarb that roaches eat and carry back to kill entire colony within days to weeks, which is effective killing method.