Whether you have an infestation or want to prepare in case you get one in the future, a roach killer is a good product to have on hand. Yes, boric acid can work very well, entering either through digestion or basic contact, but being a powder, it's messy. Wearing a mask, use the electric spray gun (included with the gallon-size jug), slightly dampen a four-inch perimeter around your house and make sure to keep children and animals away from it until it's dry (same goes for indoor application, though you'll want to apply less liberally). To truly combat roaches, your best bet is using a combination of products to prevent roaches from entering your home and kill the ones that are already there.

Effectiveness: Effectiveness is without a doubt the most important feature of a roach killer or trap. In recent years, reports of the use of heavy duty bug sprays as an illicit drug have gained notoriety. However, smaller rodents might also find their way in, at which point they will be trapped and left to suffer (as they do in traps like these).Indoxacarb: Classified by the United States EPA as a "not likely" human carcinogen, Indoxacarb is a pyrethroid also used to prevent the transmission of pathogenic microorganisms from insects to humans and other animals. Some of these roach killers and traps get the job done on contact, while others allow a roach to transport poison back to the nest and spread it to the lot. Whether you're neck-deep in cockroaches or you're just preparing for or anticipating the worst, a perimeter spray is a great measure to take both inside and out.

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Cypermethrin, Imiprothrin, Fipronil, and Indoxacarb are the more common EPA-approved ones and the active ingredients found in the products we recommend above. Note, Ortho's Home Defense Insect Killer includes Cypermethrin but also features a small concentration of Bifenthrin, which is harmful to aquatic insects and finfish, and it's best to avoid letting it leak into bodies of water. It remains temporarily lethal enough that if you spray their trail before shutting out the lights and heading off to bed, it will still harm them.