Worked great on my friends German roaches but not so well on the large American cockroach. Baited kitchen countertops every 2 feet against backspash, under microwave, inside corners of drawers. After 2 weeks found 4 adults on countertops when I turned the light on last night. I got two of them before escaping with clear Windex to kill without poisoning counters. Windex works great on all pests without staining or lasting toxicity.