Yes, bleach can kill cockroaches through ingestion or drowning. However, it is not as potent, safe, or as easy to use as traditional insecticide chemicals specifically intended to kill roaches. By ingestion, it means that you would have to make cockroaches drink the liquid solution.
While bleach is ineffective when it comes to killing cockroaches, it does repel them. But, bleach should only be used with extreme caution, as it is toxic when ingested, and has the potential to bleach or damage anything it touches. When it comes to deterring roaches with smells, bleach may not be the best option.
All biological forms are poisoned by bleach, after all. Cockroaches shouldn't be able to live off of it since humans can't. But not all bleaches are created equal; some can kill roaches. There might be better options for cockroach control than the type you use for washing.
Cockroaches have a strong sense of smell. Using natural scents works best to deter roaches. Plants such as eucalyptus, lavender, and mint are smells roaches hate.
If cockroaches get enough borax on the outside of their bodies, it actually damages their exoskeletons. This causes them to rapidly dehydrate and die; a thick coating of borax will certainly get rid of roaches overnight.
Baking soda — While it's well-relied on for everyday cleaning, baking soda is very effective at killing cockroaches too. All you need to do is mix it with something the roaches will likely consume — diced onions work well, as does sugar and cheese.
Cockroach predators include mammals, avians, amphibians and other reptiles. For example, hedgehogs will eat roaches. Joining the roach à la mode dinner party are geckos, skinks and other species of lizards, frogs, turtles, some types of birds and even rats and mice.
Bleach's Effect on Roaches
Taking a deep drink of household bleach would kill anything, roaches included. But the same strong odor that keeps people from taking a swig of bleach repels roaches as well. So though it could work, in reality, it will not. It is very difficult to kill an entire roach infestation yourself.
Boric acid can quickly kick a roach infestation to the curb. It's extremely toxic and can kill multiple generations of roaches. Mix a combination of equal parts of boric acid, sugar and water to make a dough. Roll that dough into balls or cylinders and place them where roaches will find them.
Spraying window cleaner directly onto small insects like ants or mosquitoes will kill them within a few moments. For cockroaches, window cleaner can make them temporarily unconscious so that you can squash them. This works on initial contact, but Windex will not continue to kill bugs after it has dried.
Your best bet is to combine baking soda with another granulated attractant, like sugar. Mix equal parts baking soda and sugar in a small dish and apply it to kitchen cabinets, baseboards, crevices, water sources, and other places roaches like to hide.
Windex can kill cockroaches, but only if you twist the nozzle to stream mode and spray it directly, full-strength on a single insect for at least a minute. We give it a 3/10 on our effectiveness scale.
Gel baits: According to Black, gel baits are the best roach killer option. These are available as either plastic bait stations or gel formulations that come in plastic syringes. The baits contain insecticide-laced foods that cockroaches eat.
Cockroaches are most likely to be active about four hours after dark and enter a period of immobility just afterwards. This immobility period is similar to what humans would call “sleeping.”
One popular DIY method is to mix boric acid with equal parts powdered sugar as a lure. Apply as a fine layer under appliances, behind cabinets and along crevices. Roaches ingest the mixture and die within a few hours.
Cockroach gel baits, at Walmart are a popular solution that can get rid of roaches within a couple of weeks – simply apply dots of the gel over cracks, seams and corners, along baseboards, around appliances and so on.
Crumbs and Dropped Food
Speaking of food spills, these can be another top attraction for cockroaches. If there are any crumbs or spilled drops of food on your kitchen floor at the end of the night, you can bet that the roaches will feed off these once you've gone to bed.
Roaches are attracted to similar things as any other pest: shelter, food, and water. Anything that makes these things more available and easy to access is going to contribute to a roach infestation.
It's a fact that cockroaches are afraid of humans and other mammals or animals that are bigger than them. They see us as predators and that fear triggers their instinct to scatter away. However, they dislike strong and distinctive scents such as citrus, peppermint, lavender and vinegar.
Home remedies like diatomaceous earth, baking soda, boric acid, citrus, essential oils, and borax can be effective ways to get rid of roaches. If you want to take a more aggressive approach to eliminate roaches, glue traps, bait stations, and liquid roach deterrent concentrates are all excellent options.
Baking soda can kill roaches, but in order to do so the roaches have to eat the baking soda mixture, and once they consume water the baking soda reacts with the water creating gas in their stomachs, which kills them.