Thanks. I forgot about boric acid. Under the fridge and stove and storage cupboards seems the best place to try that. I don't have oatmeal or boric acid. Where can you buy boric acid? I guess cereal or rice could replace the oatmeal. "How Does It Kill Cockroaches? When cockroaches crawl through the boric acid powder, it gets all over them, sticking to their legs, arms, etc. When the cockroach preens itself (cleans itself), it ingests the powder. If the cockroach doesn’t clean itself, its body will naturally absorb the powder anyway. Once the acid is inside the cockroach, it makes its way into the nervous and digestive systems, causing death shortly after ingestion.
Boric acid is considered so effective because cockroaches eat other dead cockroaches. As most of us are aware, cockroaches are not picky about what they do and do not each, going so far as to eat other cockroaches if they’re dead. After the cockroaches eat the one that died from the boric acid, the acid gets into their system, and the cycle continues"