Few insect pests are more persistent than the ordinary cockroach, and other than rats, few other pests elicit such an adverse reaction from homeowners and apartment dwellers. This is an insect pest that has come to symbolize filth.
There are more than 4,000 species of cockroaches, but only a few species comprise the iconic pests that commonly dwell in homes. The most common of these include:
- American cockroach (Periplaneta americana): This is the largest of the roaches found in homes, growing up to 2 inches long. Reddish-brown in color, it is most likely to be found in dark, heated areas, such as in furnace rooms or beneath stoves and water heaters.
- German cockroach (Blattella germanica): This is a smaller roach, generally growing no more than 1/2 inch long. It reproduces very fast and often enters homes in grocery containers or packaging. It has two darker stripes that run a short distance just behind the head. The overall body color can range from tan to nearly black. This is the fastest reproducer of all the roaches, going from egg to adult in 50 to 60 days.
- Oriental cockroach ((Blatta orientalis): This species is sometimes regarded as the filthiest of the cockroaches. Growing to approximately 1 inch long, it is a shiny dark brown or black color, Damp areas with decaying material will positively teem with these roaches.
- Brown-banded cockroach (Supella longipalpa): This species resembles the German cockroach, though is slightly smaller. It has visible lighter striping across the back.
Roaches are easily recognized by their flattened, elongated oval bodies and long, visible antennae. The males have two sets of wings, generally kept folded along the back, while the females are often wingless. While winged roaches are capable of flight, most species are poor fliers and generally prefer walking across surfaces.
Roaches feed on almost any organic material, thrive in the dark, warm conditions that pervade human habitats, can tolerate occasional freezing conditions, breed very quickly, and are resistant to many chemicals. They reproduce so fast that extensive infestations are nearly impossible to eradicate fully. These combined characteristics mean that controlling roaches can require almost non-stop effort in regions where they are prevalent.
The human dislike for roaches derives from the offensive odor they create and their habit of passively carrying and spreading a variety of microbes and disease-causing pathogens. Dust containing cockroach body parts is linked to many cases of allergy-induced asthma. Roaches are never welcome guests, and calling a pest control service is one way to get rid of them. But that's a costly approach, and it slathers your house with harmful chemicals. If you want to save money and avoid chemicals, here are four more natural remedies you can try.
4 Ways to Get Rid of Roaches Naturally
Borax and Powdered Sugar
Borax is a very common household cleaning powder, widely available at grocery stores. Known scientifically as sodium borate, borax is a residual mineral found in locations where seasonal lakes have evaporated away repeatedly, such as in Death Valley and other desert plains.
Combined with a sweet bait material like powdered sugar or honey, borax has long been an organic means of killing ant colonies, and it also works to kill roaches. Apply the mixture along the baseboards, in cracks, under cabinets, under sinks, and anywhere else that you've seen roaches in your house. Reapply the mixture as needed until all the bugs are gone. If you prefer, you can put your roach killer out in little containers instead of dusting the surfaces of your home with it. That'll mean less mess and less chance of coming into contact with it.
Similar but even more effective results can be achieved by combining boric acid and powdered sugar. Boric acid is essentially a more refined form of borax, and while it is not as readily available, it's worth the effort to find it if you have a severe roach problem. Use it in the same way as borax—blend it with powdered sugar or another sweet substance, apply it as a bait in dark areas, and wait for roaches to ingest it.
Keep this mixture away from children, pets, and food prep areas. Only apply borax bait in areas that your family and pets won't come into contact with. While this natural substance is not carcinogenic, borax should not be ingested or inhaled. Wear a mask when you apply the mixture and avoid inhaling it at all times. Accidental ingestion of small amounts is not very serious, but repeated ingestion can cause digestive problems and even organ damage. This is most likely if pets have repeated access to sweetened borax bait. The danger is more severe if you are using pure boric acid rather than natural borax.
Baking Soda and Sugar
Another fairly effective roach bait can also be created by blending equal amounts of ordinary kitchen baking soda and sugar. Sprinkle the combined mixture over surfaces where you want to bait the roaches—or set a small dish of the combined mixture in the target area—and wait for the roaches to consume it. While not as fast-working as borax bait, it will do the job if applied repeatedly over time.
A common substance for organic gardeners combatting slugs and snails, diatomaceous earth (DE) is a talcum-like pulverized silica stone that contains fossilized remains of marine phytoplankton. When sprinkled on an insect with a hard exoskeleton, the substance punctures the body and causes the insect to dry out and die.
However, DE is not a passive bait and it will not rid your home of roaches if you just sprinkle it over the floor. The roaches must literally be dusted with the powder for it to work. This is contrary to how DE is used by gardeners to prevent slugs and snails, where covering the ground and plants with the powder does work.
Essential Oil Sprays
In the same way that citrus oils are used as a natural pesticide for garden plants and houseplants, concoctions made from essential oils of substances such as rosemary, mint, oregano, eucalyptus, and yarrow can be an effective killer if sprayed directly on roaches. These oils do not, however, work as passive baits for simply applying to surfaces and waiting for roaches to walk across them.
It is possible to buy individual essential oils and blend them together to make your own roach killer, but there are a variety of organic commercial insect killers you can buy to do the job. These products are completely safe for pets and children, but remember that they kill only upon contact. Excess spray will need to be cleaned up to avoid staining surfaces.
What Causes Roaches?
Roaches often are introduced into homes when they migrate indoors as weather cools in the fall. Or, they can be introduced through food packaging or other containers brought into the home. Once inside, they can thrive in any warm, moist, dark areas of the home—and nearly all homes have plenty of these areas. Roaches can be especially troublesome in regions where warm, humid weather is prevalent, but any home in any climate can be plagued with roaches.
Roaches can consume almost any organic material, but messy homes with tidiness problems where human or pet food is readily available will be most prone to infestations.
How to Prevent Roaches
Keeping a tidy home and storing food in sealed containers is the best defense against roaches. Combine good hygiene with periodic inspection and repair of the home's exterior to block cracks and crevices through which roaches can enter from the outdoors. Pipe or wire entrances should be caulked to prevent insects from entering your home.
Keep foundation plantings and mulches set back from the foundation of the home to prevent nesting places for roaches. Keep firewood piles stacked well away from the house.
In areas where roaches are a habitual problem, homeowners may find it necessary to constantly bait roaches with borax/sugar mixtures.
Do roaches carry disease?
Along with houseflies, roaches are among the filthiest of insects. According to the Centers for Disease Control and Prevention (CDC), the cockroach is known to spread Salmonella typhimurium, Entamoeba histolytica, and the poliomyelitis virus mostly by tracking pathogens from contaminated, decaying material across surfaces. They also can carry pathogens in their digestive tracts, which can be passed along to the foods they feed on.
Do roaches bite?
Although rare, roaches have been known to bite humans. It's believed that this occurs under special circumstances such as a large infestation where there is a food shortage and the insect is searching for food sources it wouldn't normally turn to. But roaches are not blood feeders that deliberately seek to bite humans or animals. They feed exclusively on non-living organic materials.
How long do roaches live?
On average, cockroaches live about 1 year, though some have been known to live well past this. This relatively long lifespan, combined with a fairly rapid reproduction rate for species such as the German cockroach (egg-to-adults in 60 days or less), means that a few roaches can become an overwhelming infestation in less than a year.
When to Call a Pro
Homeowners can generally get rid of roaches themselves with natural methods, but it can take repeated, even constant treatment. If immediate complete eradication is critically important—such as if you are staging a home for a real estate showing—your best option may be to call an extermination service. But be aware that these professionals will almost certainly use some form of toxic foggers or chemical pesticides to do the job.
Control Cockroaches In and Around Your Home. Mississippi State University Extension Service.
Boric Acid General Fact Sheet. National Pesticide Information Center.
Low-Toxic Cockroach Control. University of Nebraska Extension Service.
Sharififard, Mona et al. Evaluation of Some Plant Essential Oils against the Brown-Banded Cockroach, Supella longipalpa (Blattaria: Ectobiidae): A Mechanical Vector of Human Pathogens. Journal of arthropod-borne diseases, vol. 10, no. 4, pp. 528-537, 2016.
Healthy Housing Reference Manual: Chapter 4 Disease Vectors and Pests. Centers for Disease Control and Prevention.