Cockroaches (order Blattodea) are one of the most common and oldest insects in the world that have roamed the Earth for over 300 million years. There are over 4600 types of roaches globally but are most commonly found in warm, humid climates. These insects are resilient, and pest species thrive wherever people live or work. Cockroaches are not just omnivorous scavengers, they are also harmful to our health because they crawl through unsanitary areas, cause allergies, and may trigger asthma attacks.
This guide tells you all you need to know about pest cockroaches, and how to identify the different types you can find inside and outside of your home.
Written by: A O’Neill, Licensed Pest Management Professional
Types of Cockroaches
Out of the thousands of different types of cockroaches found worldwide, 99% of these cause no problems for people.
There are around 70 different types that live in North America. While this number sounds alarming, most live in sylvatic (forested) and other natural environments.
Of these 70 types, 24 are considered exotic, meaning human travel and trade brought them from Asia, Africa, Europe, and South America.
Southern parts of the United States tend to have more structure-infesting types of roaches than northern states. For example, there are typically only three or four pest species encountered by exterminators in the Midwest, whereas more than ten pest species may be encountered in or around structures in Florida.[1]
Cockroaches are thigmotactic insects, so they search for spaces that are tight enough to touch both the top and underside of their bodies. Also, most pest cockroaches prefer dark, moist environments, which is why you’ll often find them in wall voids.
The larger, peridomestic types (live both outdoors and indoors) thrive in spaces where ventilation is poor and humidity levels stay more or less the same, such as attics and crawl spaces.
There are a few types of pest cockroaches we need to be concerned about because they are regular and economically important invaders of our homes and workplaces. And these are:
The German cockroach (Blattella germanica) lives entirely indoors
The American Cockroach (Periplaneta Americana)
The Oriental cockroach (Blatta orientalis)
Credit: Clemson University – USDA Cooperative Extension Slide Series, Bugwood.org
The Smokybrown cockroach (Periplaneta fuliginosa)
The Brown-Banded cockroach (Supella longipalpa).
Is a Cockroach the same as a roach?
Yes, a cockroach and a roach are the same. The word “cockroach” is shortened to “roach,” and both forms are used interchangeably.
What Do Roaches Look Like?
Cockroaches belong to the order Blattaria (also referred to as Blattodea). Although each species looks different, there are three main factors that help identify which kind of roach it is: size, color, and whether or not they have markings on their pronotum.
How To Identify a Cockroach
In addition to the above three characteristics, they also have certain other features in common that will tell you if it’s a cockroach, which are:
- Laterally flattened with oval-shaped bodies that enable them to squeeze into tight cracks and crevices.
- Small head that is surrounded by a shield-like pronotum
- The mouth points down and in a backward direction
- 2 long, thin antennae that have many segments and are usually the same length as their body
- Brown to black in color
- 6 spiny legs which have tiny sensory hairs and claws which help them to climb and run across ceilings
- Hind legs are longer than the other legs
- Most species of cockroach have wings that fold flat on their backs, but not all can fly
- Range in size from 1/2 inch (13 mm) to 3 inches (76 mm) in length
It’s common to panic when you think you’ve seen one in your home, but first, make sure it definitely is this pest and not one of these bugs that look like cockroaches as treatments for roach infestations will be different from treatments for other insects, so it’s important to accurately identify them.
Related: Pictures of roaches
Different Types of Cockroaches
These are the type of pest roaches that are among the most likely to invade your home.
| Species | Appearance (adult) | Can this species fly? | Habitat | How it enters your home |
| German cockroach – Small domestic and most common household cockroach | Size: 1/2 inch (13 mm) Color: light brown to tan Pronotum marking: two dark parallel stripes | Both sexes have wings, they can glide if they have to but do not fly | Found in homes and workplaces. Prefers warm & humid areas in kitchens and bathrooms | Usually brought in by accident with your deliveries, in your grocery bags, used furniture, etc. |
| American cockroach – Large peridomestic roach, also known as a ‘sewer roach’ and ‘palmetto bug’. | Size: 2 inches (50 mm) Color: reddish-brown Pronotum marking: reddish-brown with a yellow-colored band around the edge | Both sexes can fly as they have fully developed wings that cover entire abdomens. | Prefer the outdoors in warmer months. Can be found in sewers. | Enters homes through drains, gaps around utility pipes, cracks in walls, and around windows. |
| Oriental cockroach – Large peridomestic roach – sometimes called ‘black beetle cockroach’. | Size: Males – 1 inch (25 mm) and females – 1.25 inches (32 mm). Color: Shiny dark brown to black. Pronotum marking: Shiny dark brown to black – no markings. | Males have wings covering 3/4 of the body. Females have wing pads. Neither can fly | Prefers damp places like landfills, sewers, drains. Summer months they look for cooler humid areas in crawlspaces, basements, garages. | Through gaps and cracks in foundations and walls. They can crawl under doors and through air ducts. Large numbers can crawl up through drains and pipes. |
| Smokybrown cockroach – Peridomestic roach | Size: 1.5 inches (38 mm). Color: Mahogany brown. Pronotum marking: dark brown – no markings. | Male and females can fly as they have fully developed wings. | Outdoors found in tree holes, leaf litter, rain gutters, sewers. Indoors, found in attics and crawlspaces as needs warm, poorly ventilated, high humidity areas as prone to drying out. | can be brought in with firewood, or fly in through a gap in a door or window. Also crack in foundation walls and gaps around utility lines can provide a way in. |
| Brown-banded cockroaches – Small domestic roach. | Size: 1/2 inch (13 mm). Color: Light-brown to mid-brown with two yellow-brown bands across the middle and lower sections of wings. Pronotum marking: Dark brown to black with a bell-shaped pattern and translucent border. | Females have wings that cover 3/4 of the abdomen – cannot fly. Males have full-length wings – can fly. | Prefers warm drier areas, usually found higher up in rooms behind moldings, picture frames. Also known as ‘furniture cockroach’ as found under and inside upholstered furniture. | Several ways such as in boxes, grocery products, electrical items, and infested furniture. |
What Do Baby Cockroaches Look Like?
Generally, nymphs look like adults in shape and are obviously smaller. They are also wingless and can differ in color, as explained below.
What Do Cockroaches Look Like When They First Hatch?
When the immature nymph first emerges from the egg sac or ootheca, it looks like a white roach, but after several hours, its body hardens and, its color darkens.
They are also white after each molt and people often mistakenly think they’ve seen an albino roach. After shedding its exoskeleton, a cockroach is temporarily white because it lacks pigment in its body. Within a few hours, the new exoskeleton hardens, and the characteristic color and pattern of the species form.
Do Baby Cockroaches Fly?
No, baby cockroaches of any species cannot fly because they do not have wings. Their wings only develop when they reach the final molt and become adults.
But just like the adult roaches, they can scurry around very quickly.
Unfortunately, if you see any shed skins or white nymphs in your home, you have a cockroach infestation. And just like adults, nymphs can also have the same disease-causing bacteria on their bodies.
Can Adult Cockroaches Fly?
Yes, most types of roach have wings, so many of them can fly or glide. However, they tend not to be good flyers and prefer to crawl and scurry as they are extremely fast runners.
The table above tells you which cockroaches can and cannot fly.
What Do Cockroaches Eat?
Roaches are omnivores, so they’ll eat almost any organic matter they find, but their preference is for starchy foods, such as cereals and sugary items. So, what attracts cockroaches in your home? A roach’s diet includes a variety of food sources that they can find in your home, such as decaying meat and plants, dead insects, garbage, paper and cardboard, soap, pet food, feces, and toothpaste.
Researchers have successfully used bread soaked in beer inside traps to attract and capture roaches. These pests are serious scavengers.
Why Are Roaches So Gross?
They are disgusting because when scavenging in unsanitary places such as sewers, they pick up all sorts of harmful bacteria that they then leave on our food and countertops when they walk across them. They also contaminate food and food preparation areas by leaving behind their droppings and vomiting up the contents of their stomach.
According to the World Health Organisation:
Cockroaches are proven or suspected carriers of the organisms causing: diarrhea, dysentery, cholera, leprosy, plague, typhoid fever, viral diseases such as poliomyelitis.[1]
DID YOU KNOW?
Cockroaches can spread 6 types of parasitic worms, 33 Kinds of bacteria, including E. Coli & Salmonella, and 7 kinds of human pathogens[2]
And if that’s not bad enough, roaches are bad for your health in other ways as some people are also allergic to their feces (poop), shed skins, and saliva which can trigger asthma attacks.
In fact, cockroaches are the Number 1 cause of indoor allergens globally.[3]
Does Anything Eat These Pests?
In the wild, cockroaches have many natural predators. But you probably want to know if there is anything inside your home that will munch on a roach infestation. There are, but they won’t reduce the number of roaches that much to eliminate them.
In your home, roaches will generally die from old age, be eaten by other roaches if food is limited and the infestation is growing, or from pest control treatments such as eating gel bait.
How Do You Get Cockroaches In Your Home?
The reasons that pests, like cockroaches, are attracted to your home are usually for food and water sources, shelter, and warmth.
In short, your home provides a place where these pests can thrive.
But how do they get in? Well, there are a number of ways, including:
- in deliveries – this is the main way German roaches get into your home
- hiding in grocery bags
- through cracks and gaps in windows, vents, pipes, and drains
- firewood
- in cardboard boxes
- gaps under doors
These are just a few examples of how roaches get into your home, but you can see just how easily they can enter unnoticed.
Cockroach Infestation Signs – What to Look For
As most types of roaches are nocturnal and hide away during the day, there is a good chance that you’ll see the first signs of an infestation before you’ve even seen one scurrying across your floor.
However, there are some common clues to look out for:
- Fecal droppings (frass) – cockroach droppings are the most obvious sign of a roach infestation. Depending on which cockroach type has invaded your home, the feces produced will look different. Small roaches, such as the German roach produce droppings that look like tiny specks of black pepper or coffee grounds. The larger roaches, such as the American species produce droppings that are pellet-shaped and can be mistaken for mouse droppings.
- Smear marks – roach smear marks are easy to identify since they are irregular-shaped visible traces of brown feces. The area where the smear is located is usually wet or has a high moisture level such as in sinks and floor-wall junctions.
- Egg capsules (ootheca) – are oval-shaped, brown in color, and contain a number of eggs. These are usually hidden out of the way of any predators of cockroaches, such as spiders and cats. So if you find any egg cases, then you can be sure you have a roach problem.
- Cast or Shed skins – are mainly found in areas where they group together. The skins are left behind as the roach grows and sheds its skin revealing a white roach until pigmentation in the skin is restored, which usually takes a few hours.
- An unpleasant musty, oily odor will be noticeable as the infestation grows and is another way to identify an infestation of roaches. The pungent smell comes from their feces when they leave their droppings and becomes more detectable as they increase in number and in areas where they congregate.
- Live roaches – of course, one of the most obvious signs you have a roach infestation is actually finding one (or a few) in your home scurrying around at night when you turn the light on. You’ll start to see them during the day as the infestation gets bigger.
Finding and Eliminating Cockroaches
You’ve now you’ve got a better idea of what cockroaches are and the different types that can hide in your home. If you’re unsure whether you have cockroaches, place sticky traps flush against the walls on countertops behind the microwave and other appliances, underneath the fridge, and oven, but make sure they don’t touch the motors.
Read all about getting rid of cockroaches and how to apply gel bait.
However, these traps should only be used to detect and monitor the presence of cockroaches and not used solely as a way to get rid of them.
There are a number of control products to eliminate these pests, such as gel baits and insecticides that you can use if you feel comfortable doing your own cockroach pest control and as long as you don’t have a large infestation.
Alternatively, contact a reputable pest control company to eliminate the infestation for you. Either way, deal with this immediately because seeing a cockroach in your home can be a worrying sign.
Related Pages:
What Attracts Cockroaches To Your Home?
German Cockroaches – The Public Health Pest
This Is Why You See Cockroaches Outside Your Home
Florida woods cockroaches
[1] https://www.who.int/water_sanitation_health/resources/vector288to301.pdf
[2] pctonline.com
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3423599/
