Bought this for a sudden roach infestation this summer. It was the cheapest boric acid and largest container that I could find locally. I spread it along the home entrances, on window sills and kitchen counters, along the floor boards and behind the fridge and stove...After about 2 days I began to see dead adult and baby roaches which tells me this product works. It is now about 2 weeks and I have not seen any more roaches. My only dislike is that the instructions says to put down a fine dusting of the powder but the design of the container and nozzle does not allow that to be done.