The German cockroach (Blattella germanica) is a common pest in buildings throughout the world. It spreads pathogens that can cause diarrheal disease and allergens that can cause lung hypersensitivity in vulnerable people. Insecticide sprays and insecticide-loaded baits have been used to control B. germanica for decades, but there is evidence that some populations have developed resistance to insecticides. https://entomologytoday.org/2022/01/27/california-insecticide-resistance-german-cockroaches/