Cockroaches have been pestering humans throughout history – likely to the first human settlements that were established. But cockroaches themselves go much further back in history.
The oldest cockroach fossils are around 145 million years old! With over 4,600 species, the cockroaches are a diverse and ubiquitous species. So many types of cockroaches, but the vast majority never come into contact with humans or try to invade your home.
In fact, only around 30 species are known to live in human habitats. Of these, only a handful have made their way to the United States.
In this article, we will take a quick look at all of the most common types of cockroach species found in North American homes. Check it out to learn where they live, how big they get, and how to identify each species!
Most Common Cockroach Species in United States
- Where is it found?: Global Distribution
- Size: About 1/2 to 5/8 inches long
- Habitat: Near Water (prefers Kitchens, Bathrooms)
- Distinct Traits: Tan to black, two parallel streaks of color behind the head
The German Cockroach is likely the most widespread pest species. Though more recent scientific studies have shown that the cockroach likely did not originate in Germany, this species has now made it to the farthest reaches of the globe – hitching rides with the human population.
The German Cockroach is the most common cockroach to find in your home. If the cockroaches you’re seeing are mostly “small”, they’re likely German Cockroaches as they max out at about a half inch long.
Compared to other roaches, this species has a high need for water. As such, you will likely find harborages around the kitchen, laundry, and bathroom. While this species has wings, they are not competent flyers and prefer to scurry away when disturbed.
- Where is it found?: Global Distribution, temperate to tropical
- Size: About 1.5 to 2 inches long – one of the largest!
- Habitat: Often found in moist basements, sewers, and crawl spaces
- Distinct Traits: Flattened oval body, Reddish Brown, often with a yellow “ring” area near the head
The American Cockroach is only slightly outcompeted by the German cockroach because of its temperature tolerance. American cockroaches need areas that remain slightly warmer (about 70° F), whereas the German cockroach can survive temperatures about 10° lower.
Still, the American cockroach has a global distribution and has followed humans to many different parts of the globe. The name “American” is also a misnomer since the cockroach is likely native to Africa and the Middle East.
American cockroaches are most commonly found in commercial buildings. They often hitchhike between buildings in cardboard boxes, equipment, backpacks, and more. Cockroaches can be a big problem in hospitals due to the evidence of them carrying bacteria and pathogens.
American cockroaches are strong fliers, allowing them to congregate outdoors and migrate to different buildings during the fall to take shelter before the cold winter temperatures approach.
- Where is it found?: Global Distribution, common in the Northwest, Midwest, and Southern US
- Size: About 1 to 1.25 inches long
- Habitat: Prefer very dark, moist places like sewers, swampy basements, and outside
- Distinct Traits: Dark brown to black, with a very glossy exoskeleton. Males have wings covering about 75% of the abdomen, females have tiny wings and a wider head.
The Oriental Cockroach, compared to the common varieties above, is slightly more inclined to live outside among leaf litter and under bushes. However, it will sometimes occupy commercial facilities that have damp basements, sewers, and drains.
These cockroaches have a noticeably dark coloration. While the males have wings and can fly short distances, the females have vestigial wings and cannot fly. Since they live close to water sources, this species can be hard to get rid of if the insecticide application is washed away quickly.
These roaches are extremely pungent!
- Where is it found?: Northern Latitudes, common in Northeastern, Southern, and Midwest US
- Size: About 1/2 inches
- Habitat: Prefer indoor dry areas maintained at a high temperature
- Distinct Traits: Yellow-brown bands on the abdomen
The Brown-banded Cockroach is another migrant to America, likely coming from parts of Africa, through Cuba, and into the United States.
While the species is fairly widely distributed in the US, it is most common in humid areas of the Northeast, South, and Midwest.
Compared to the German cockroach, the Brown-banded cockroach prefer more dry conditions. Harborages may be found in bedrooms, living rooms, and other areas with no immediate access to water.
These cockroaches also prefer to hideout higher off the ground than most cockroaches. They might be in closets, furniture, crown molding, appliances, etc.
Smoky Brown Cockroach
- Where is it found?: Southern United States (Florida, North Carolina, Louisiana, Mississippi, Texas)
- Size: About 1.25 inches long
- Habitat: Tropical areas, in moist areas around the perimeter of buildings
- Distinct Traits: Dark Mahogany coloration, similar in shape to the American Cockroach, wings that cover the entire abdomen
The Smoky Brown Cockroach is a tropical species of cockroach that has made its way into parts of the Southern United States. Unlike its close relative, the American Cockroach, this species requires much more water and cannot tolerate any amount of cold temperatures.
The smoky brown cockroach has a very dark coloration and large size. It’s a strong flier and is attracted to light. These bugs are most commonly found outdoors around wood piles, debris, vacant buildings, and palm trees.
The Smoky Brown Cockroach may also infest a building if it finds a suitable habitat. Hot buildings like garages or attics with little ventilation can be ideal places for them to live.
- Where is it found?: Southern United States (mostly Southern Florida)
- Size: About 1.5 inches
- Habitat: Tropical areas, prefers outdoors but will move inside to survive cold spells
- Distinct Traits: Reddish-brown to dark-brown, very large wings, large head-shield with yellow margins
The Australian Cockroach is a very tropical species that prefers fresh plant material more than some of its cousins. Because of this, the Australian cockroach is rarely found indoors when the temperature and weather are pleasant.
Unlike many domestic species of cockroach, this peridomestic species has very large wings and is fully capable of long flights. Nymphs of this species have distinct black and translucent bands, with adults growing a large head shield that gives the appearance of two large eyes.
The Australian Cockroach looks very similar to the American Cockroach, but it’s about half an inch smaller and has noticeable yellow stripes on the side of the body behind the head.
- Where is it found?: Circumtropical (Introduced to many tropical areas globally)
- Size: About 1.5” (4 cm)
- Habitat: Very humid tropical areas
- Distinct Traits: A completely reddish-brown cockroach that resembles the American Cockroach.
Though the Brown Cockroach is less common in the US than some of the other species presented here, you may run into this insect from time to time. It’s most common in the southeast and Mid-Atlantic states.
In general, this species resembles the American cockroach, though it has a much more consistent color and is much thicker and shorter. This species is known to invade indoor areas when temperatures start dropping, though it is most commonly found outdoors.
This cockroach likes to feed on plant matter. It can sometimes be found in greenhouses as well as other commercial facilities and rarely in the home.
Pennsylvania Wood Cockroach
- Where is it found?: Eastern and Central United States
- Size: About ½” – 1” (1.2-2.5 cm)
- Habitat: Prefers open areas with lots of timber
- Distinct Traits: Dark brown and glossy, with females having only vestigial wings, cream edges on the area behind the head
The Pennsylvania Wood Cockroach – as its name implies – prefers to live in and around fallen wood. While this species is most commonly found outdoors, an infestation can sometimes occur when the cockroaches hitch a ride on firewood into a home.
Though the females are flightless, the males can fly long distances and are attracted to light at night. This often leads to males finding their way indoors. Like other peridomestic species, infestations in the home are rare – but can happen when the weather or temperature precludes them from living outdoors.
No treatment is needed when you find these cockroaches inside as they don’t typically survive indoors. They can be vacuumed up or tossed outside and you can prevent other invaders by sealing cracks that are allowing them entry.
- Where is it found?: Tropical and Subtropical Regions
- Size: About 1” (2.5 cm)
- Habitat: Prefers to burrow in rich soils, sometimes inhabits greenhouses
- Distinct Traits: Adults have a very dark head shield, with a yellow-to-white edge on the head side, light brown wings covering the body
The Surinam Cockroach – also known as the Greenhouse Cockroach – is a tropical species that has specialized to burrow into the soil.
Interestingly, populations of Surinam cockroaches are entirely female. Females reproduce through a process called parthenogenesis, whereby a female can self-fertilize and propagate without needing a male.
While this species is rarely an indoor pest because of their need for moist soils, they are often imported in the soil of plants and can infest greenhouses, gardens, and grow rooms.
These cockroaches typically stay hidden during the day and come out at night to feed on plant matter.
General Information about Cockroaches
Now that you have some information about the various species of cockroach you may encounter in the United States, there is also some more general information about cockroaches that you might find useful if they have invaded your space!
The first thing you should know is that cockroaches are a gregarious species. This means that a single cockroach gets more comfortable when it is around other cockroaches. While cockroaches are not a truly “social” species like bees or ants, they tend to live in places known as “harborages.” A harborage is simply a warm, dark place where several cockroaches retreat during the day.
Interestingly, studies have shown that individual cockroaches make a decision to stay in a place or move on based on the number of other cockroaches occupying that space. If there are no other cockroaches, the individual takes it as a signal that the food supply has run out. If there are many cockroaches in a harborage, each individual is much more likely to stay. When it comes to eradication, this trait can give you a huge advantage. You don’t have to kill every single cockroach, you simply have to reduce their numbers to the point that they make the decision to abandon their harborage. This is easily accomplished by removing their food source or killing off a majority of the individuals!
Second, you should also know that most cockroach species are not opposed to eating each other – or each other’s feces! This can also help you eradicate an infestation. By removing their food source, the cockroaches will be forced to cannibalize each other and clean up the harborage that they were occupying. This trait can not only help you get rid of an infestation but will help reduce the dusty allergens produced by the harborage as you reduce the population!
Lastly, it’s important to note that most cockroaches actively avoid light sources. This has both benefits and drawbacks. On the one hand, if you turn the light on in your kitchen and a cockroach scurries away, you should know that hundreds more are probably hiding in the dark. At the same time, if you find a harborage you can encourage the roaches to disperse by leaving a bright light on the harborage area at all times and repeatedly disturbing the area to ensure that the cockroaches do not feel safe.