Cockroaches are ancient bugs with origins dating back an estimated 320 million years. They are some of the most adaptable, hardy creatures on Earth. Cockroaches can be found throughout the world, from extreme cold in the Arctic to the heat and humidity of the tropics. Not only do they have a wide geographical range, but they can live in many different habitats including: forests, deserts, water, and in human homes. Although there are over 4,600 species of cockroaches, only approximately 30 are known to frequent human habitats, and approximately four species are well-known pests.¹ That being said, they are still among the most common household pests in the world. This ultimate guide to cockroaches will provide all the information you will need to be able to identify common species, understand cockroach behavior, and learn methods of prevention and elimination.
Identifying Common Cockroach Species
In the United States, there are four common species of cockroaches that get into homes and cause problems: German, American, brown-banded, and Oriental cockroaches. Although they vary in size and color, they all have small heads with broad flattened bodies. Cockroaches also have 6 legs, large compound eyes, and long antennae that are roughly the length of their bodies. Here is a closer look at the common species and some of their unique characteristics.
German cockroaches are found throughout the world and are the most common kind of cockroach in the United States.
Size: ½” – ⅝”
Description: Flat, oval-shaped; Light to dark brown with 2 darker bands behind the head
Preferred Diet: sweets and starches
Habitat: Warm, moist places like kitchens, bathrooms, near plumbing, under sinks, in cupboards, etc; Preferred temperature range is between 70-75 degrees F.
American cockroaches are the largest of the four common species. Although they can be found in homes, they are more common in buildings like restaurants, grocery stores, and hospitals.
Size: 1.5” – 2”
Description: Flat, oval-shaped; Reddish-brown with faint markings that sometimes appear as a yellowish figure 8 on the back of the head; Long wings that cover the abdomen
Preferred Diet: Eat almost anything like plants, leather, dead skin flakes, pantry foods, and other insects
Habitat: Warm, dark, wet areas like sewers, basements, under sinks, in drains; Preferred temperature is over 82 degrees F.
When compared to other common cockroaches, the brown-banded cockroach lives in higher locations and is less dependent on moisture. This means that instead of remaining only in one room like a kitchen or bathroom, brown-banded cockroaches can be widely spread throughout the entire house.
Description: Flat and oval-shaped; Brown with light stripes across the wings; Females are darker brown and tear-drop shaped; Males are brownish-gold with a more narrow body and larger wings
Preferred Diet: Starchy foods, as well as things like wallpaper paste and book bindings
Habitat: Any room in the home; Often found behind pictures or clocks on the walls or in warm areas like behind TV’s or other appliances; Preferred temperature is over 80 degrees F.
Oriental cockroaches were most likely brought to America by ships, but are actually native to Africa. They are large, dirty roaches with a very strong smell. Oriental cockroaches are also sometimes called “water bugs.”
Size:1” – 1.25”
Description: Oval-shaped; Very dark brown to black in color; Females have very short, stubby wings; Males’ wings are longer, but still shorter than the body
Preferred Diet: Garbage, sewage, organic matter, anything it can scavenge
Habitat: Prefers dirty places like sewers, basements, drains, leaky pipes, under sinks, laundry rooms; Can survive in cooler environments and prefers less than 84 degrees F.
Attribution: By gailhampshire from Cradley, Malvern, U.K (Oriental Cockroach. Blatta orientalis) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons
Impact of Cockroaches on Humans
The cockroach’s distinction as a pest comes from a couple of different impacts that they have on humans. While some view them as purely a nuisance because they cause anxiety and emit a bad smell, cockroaches can also spread disease, damage property, and cause allergies and asthma. A brief look at each of these will give a better understanding of why roach control is essential.
Anxiety and Repulsion
Cockroaches are repulsive to almost all humans because of their propensity for living in sewers and other unsanitary conditions, the idea that they eat garbage and feces, their quick skittish movements, and their aversion to light. In fact, research has shown that they are one of the most feared insects. Jeff Lockwood, a professor of natural science and humanities at the University of Wyoming said, “The things we find so repulsive about roaches are all a matter of those creatures’ biology. Cockroaches tap into this sort of evolutionary aversion we have to greasy, smelly, slimy things.” So, it turns out that most people want cockroaches out of their house for no other reason than that they are repulsive.
Cockroaches secrete a substance from their mouth and glands that gives off a long-lasting, offensive odor that smells oily and musty. The more cockroaches that are present, the stronger the odor will be.
Property Damage from Cockroaches
Cockroaches will eat almost anything, and that often includes paper products, book bindings, and glue. Large roaches will gnaw on books and other sources of these starches. A large infestation can cause significant damage. Cockroaches can also contaminate food and utensils and cause fecal stains on walls, fabric, and other surfaces.
Cockroaches and Disease Transmission
It has long been known that cockroaches carry human pathogens like salmonella and E. coli. Since roaches live and move from sewers and bathrooms into kitchens and dining rooms, it is no wonder that they can make humans sick. They can cause intestinal distress and diseases like diarrhea, dysentery, typhoid and cholera.
Allergens and Asthma from Cockroaches
A relatively new study on cockroaches discovered that they cause allergies and are major contributors to asthma, especially in children. Cockroach saliva, excrement, molted skin, and exoskeletons contain a protein that is a major trigger in people susceptible to allergies. A tendency toward allergies combined with high exposure to the cockroach allergens can increase the risk of asthma in certain populations. According to Kenneth Olden, the NIEHS director, “These data confirm that cockroach allergen is the primary contributor to childhood asthma in inner-city home environments.” This new understanding of the impact that cockroaches have on our children and society has made effective cockroach control even more important.
Cockroach Prevention Methods
In order to minimize the impact that cockroaches have on humans, prevention methods are important to understand and implement. Cockroaches enter homes in search of food, water, and shelter, so making these things less accessible is the ultimate goal. This is done through sanitation and exclusion efforts. Here are some tips and tricks to help prevent cockroaches.
- Eliminate food crumbs by sweeping and vacuuming frequently
- Don’t leave food out overnight
- Store excess food in the refrigerator or an air-tight container
- Wash dishes immediately after use
- Take out the trash daily and use a lid that keeps it tightly covered
- Don’t leave your pet’s food and water out overnight
- Only eat in the kitchen and dining room
- Wipe counters regularly and clean up spills
- Repair any leaky faucets or pipes
- Check basements and crawl spaces for moisture problems
- Declutter the home by removing extra cardboard boxes, newspapers, bags, etc.
- Seal the exterior of the house using caulk for small cracks or steel wool and expandable spray foam for larger holes and gaps
Cockroach Control Methods
Cockroach control comes with a few challenges. First, cockroaches tend to live in cracks and crevices that are hard to reach, and they normally are only active at night. This makes treatment difficult. Secondly, like many other pests, some cockroaches have developed a resistance to certain types of insecticides. The solution to both of these problems is to use multiple approaches that involve both non-chemical and chemical means.
Non-Chemical Cockroach Control
Apart from using the above mentioned prevention methods, there are some non-chemical things that you can also do to get rid of cockroaches in your home. Physical removal of the bugs is one approach. Use a vacuum to remove adults, nymphs, and eggs from hard to reach areas. A crevice tool is helpful for this step. Thoroughly vacuum all areas where cockroaches like to hide or have been seen including: kitchens, pantries, drawers, cupboards, bathrooms, baseboards, under sinks, behind appliances, storage areas, garages, basements, etc. While physical removal is not a perfect solution, it can be quite effective when combined with other treatments.
Another method of physical removal involves sticky traps. These traps are not likely to remove enough cockroaches by themselves, but they can be a great way to monitor the cockroach population in your home. Place these traps right next to baseboards for optimal effectiveness. You can place them in many different areas of your home so that you can identify problem spots to treat more thoroughly.
Chemical Cockroach Control
There are several different means of chemical control for cockroaches including baits, dusts (powders), and sprays (liquid or aerosol). With any chemical, it is extremely important to always read and follow the label directions. Each method has advantages and disadvantages, and often the best course of action is to employ multiple approaches.
Foggers/Bug bombs: The use of foggers is not generally recommended for most cockroach infestations. Foggers do not allow for targeted use and do not penetrate deep enough in cracks and crevices to kill all the roaches. They are mostly effective against flying insects, but may be helpful in killing roaches that are out in the open. Since it is rare for roaches to be in plain site, other methods are usually better. If you choose to use a fogger, precaution should be taken and all directions followed.
Cockroach baits: Baits are most effective when the infestation is still relatively small and when sanitation measures have been implemented in the living space. If there is no other readily available food around, baits will be more likely to attract cockroaches. Place multiple baits around roach hotspots. Baits can be in gel form or in a ready to use plastic container. The advantage of baits is that they can be placed in a very precise location, but they are often slow acting and patience is required.
Sprays (liquid and aerosol): Spray insecticides can be used to treat in and around infested areas in a home. Along baseboards, under sinks and behind appliances are all high priorities for treatment of roaches. Most sprays use permethrin, deltamethrin, cyfluthrin, or cypermethrin as the active ingredient. Sprays are great because they can be used in large general areas as well as smaller, specific places. Some sprays are residual and will continue to work for months. Perimeter sprays can also be used around the outside of the home to keep cockroaches and many other different pests from entering.
Dusts/Powders: Dusts, combined with sprays, are the preferred method for most cockroach infestations. These dusts are usually desiccants, which means that they dry out the insect. Boric acid, silica, or diatomaceous earth are common dusts. They can be applied to cracks, crevices, behind appliances and baseboards, under sinks, and other hard to reach areas. They often come in a squeeze bottle for ease of use.
Cockroaches have been bothering humans for thousands of years, but with a little knowledge and some great Harris cockroach products, effective control can be achieved. Our products are EPA registered and approved and can help frustrated residents take back their homes. The Harris name has been around in pest control for over 90 years and is still a leader in the industry. When cockroaches get you down, choose Harris to help send them packing once and for all.