Despite their name, American cockroaches originate from tropical Africa and the Middle East. They don’t make much noise and only emit a musty odor in large numbers. Out of all the cockroaches that invade homes, the American cockroach is the largest.
American cockroaches (Periplaneta americana) are reddish-brown. The adults have wings and can fly short distances, but nymphs can’t. They also reach around 1.5 to 2 inches long. They’re the longest-lived of all cockroaches that infest the home, as they’re able to survive for up to 2 years. They prefer to nest near food sources, such as the kitchen or pantry.
To get rid of American cockroaches, you need to use insecticides. They will fall victim to sprays, bait, and boric acid. Diatomaceous earth is also effective. While you’re applying these measures, seal off any gaps in your windows, doors, and the home’s skirting. This will prevent more cockroaches from coming in.
How To Identify An American Cockroach
You can identify American cockroaches based on their:
- Color: Reddish-brown at their heads, but darker brown across the body. They also have a yellowish figure of 8 pattern on their heads.
- Size: Adult cockroaches are about 1.5 inches in length, but can grow as large as 2 inches.
- Legs: American cockroaches have 6 legs – 3 on each side.
- Shape: The body is oval and flat with long, thin wings.
- Antennae: American cockroaches have long antennae protruding from their heads.
- Wings: Adult American cockroaches have wings (although nymphs don’t).
American Cockroach Information
As mentioned, the American cockroach hails from Africa and the Middle East. It’s believed to have traveled to the Americas from the 17th century onward on trading ships due to the Atlantic Slave Trade. This is why the species is also known by another name: the ship cockroach. Its navel exploits have taken it all around the world, and along the way, it’s earned more names:
- Kakerlac. This is the Danish word for cockroach, as the sea-faring Danes likely had encounters with this common pest.
- The Bombay Canary. The tightly-populated city of Mumbai (formally known as Bombay) saw these cockroaches thrive. They reached such large sizes that they were inaccurately compared to small birds.
How Big Can An American Cockroach Get?
While American cockroaches aren’t the biggest cockroach species in the world, they’re the largest household species. Males vary between 1.4 inches and 1.6 inches. However, it’s not uncommon to see females that are up to 2 inches. Their stocky body and long wings match their size.
Why Are American Cockroaches So Big?
It was once believed that organisms that have access to richer oxygen would grow larger and faster. Cockroaches defy the natural order.
In a study by the Geological Society Of America, cockroaches were kept in a controlled environment with varying oxygen levels. While other insects exposed to more concentrated amounts of oxygen thrived, cockroaches didn’t. Instead, they remained small and grew more slowly.
Researchers found the answer in the cockroach’s tracheal tubes. These are instrumental to a cockroach’s ability to breathe. For the test subjects with higher oxygen exposure, their tracheal tubes grew smaller. Researchers believe that, instead of expanding them to take in more oxygen, cockroaches devoted their internal resources to enhancing digestion and reproduction.
In other words, instead of trying to process the oxygen and grow to a large size, cockroaches picked their favorite areas to enhance. Eating and making more cockroaches was more important to their survival.
How Long Does An American Cockroach Live?
Along with their impressive sizes, American cockroaches are one of the most long-lived species. While other household types cap out at 6 months, the average American cockroach lives for up to 1 year.
Interestingly, female American cockroaches can live for up to 2 years. The reason for this is attributed to the female’s duty to produce eggs. Since females produce only 1 egg case every month, longevity is essential.
A male will continue to breed with other females, but the pregnant female needs to stay alive to ensure the next generation comes into being. Of course, the lifespan of American cockroaches depends on many factors. This includes:
- The climate
- Their diet
- Natural predators
- Exposure to pesticides
While two years is the maximum lifespan, most only live for 9-12 months.
How Many American Cockroaches Are In One Egg?
After mating, a female American cockroach will produce an egg sac, called an ootheca. Inside this capsule-like container, there will be around 16-18 eggs. Each of these will eventually hatch into a baby cockroach.
While other species can fit up to 50 eggs in one sac, American cockroaches don’t. Instead, they rely on their longer lifespan to increase their numbers.
What Do American Cockroaches Eat?
American cockroaches prefer the outdoors and are found naturally in forested areas. As such, their main food sources include:
- Rotting wood
- Decaying leaves
- Moss and mold
- Animal and insect carcasses
With that said, American cockroaches are omnivores that eat an extensive range of foods. As long as it’s organic and can be gnawed at with its mandibles, cockroaches will use anything as a source of nutritional value. American cockroaches will eat:
- Leftover food
- Crumbs and spills
- Paper and cardboard
- House plants
- Rotting fruit
- Book bindings
- Skin flakes
In a bind, cockroaches will even eat flaking paint from your appliances. It may not sustain them for long, but American cockroaches can survive up to one month without food. Any small traces of organic matter will tide them over until a more nourishing meal becomes available. Although they can only survive a week without water, so they’ll perish quicker if their environment doesn’t have liquid.
They’re also prone to eating starch-based matter, which is one of their favorite food sources. Cockroaches can digest cellulose, which enables them to eat paper and glue.
What Do American Cockroaches Smell Like?
American cockroaches smell musty and produce an unpleasant odor that becomes worse the larger the infestation gets. It’s likely undetectable in small numbers, but if the cockroaches gather in large numbers and you discover their nest, the smell may be strong enough to notice. The smell comes from:
- Pheromones. Cockroaches emit pheromones called cuticular hydrocarbons that they use to communicate and attract mates. This even helps the cockroaches leave scent trails, leading to food and shelter.
- Waste and Mold. Cockroaches traipse through bacteria, poop, dead things, and mold. All this builds up and may leave behind a smell in their nest.
- Death Stench. Cockroaches also emit a specific pheromone when they die. This warns all other cockroaches to run away from the danger.
Do American Cockroaches Make Noise?
American cockroaches do not have a specific call, chirp, or hiss. They are mostly silent and instead communicate through pheromones. However, you can hear audible fluttering wings in large colonies.
You may hear an American cockroach if you listen closely. Unintentionally, they may create a sound by:
- Brushing against other objects
- By flapping or fluttering their wings
- By crawling over each other in a nest
- By burrowing through wall insulation or wiring in your electronics
This won’t be as distinct as a rat or mouse scurrying around. However, if you notice a slight crinkling sound from behind your refrigerator or in the back of your closet, take notice. When the sound becomes obvious, that means you have a large infestation.
Does The American Cockroach Fly?
American cockroaches have fully functional wings and can fly. The appendages are long and thin, laid on their backs with another protective set of wings over the inner ones. This helps shield the cockroaches from outside damage, aids their escape from predators, and enables them to reach vantage points.
While many household cockroaches don’t use their wings for anything but protection, American cockroaches do. They can fly for short distances and glide from higher vantage points. They don’t have the greatest coordination, but the wings still help them flutter over 5 feet in one second.
What Do American Cockroach Droppings Look Like?
Cockroach poop is usually the first sign of an infestation. These droppings are tiny, looking much like coffee grounds. Cockroaches poop wherever they are, without a designated toilet area. Because of this, if you see a large batch of droppings, you definitely have a colony nearby.
The droppings of an American cockroach are very distinct. This can help you set them apart from other household species. Check if the poop is:
- Solid and well-formed
- Cylindrical in shape
- Black or brown
- 2 millimeters in size
- Has ridges from one end to the other
American Cockroach Droppings Vs. Mouse Droppings
At a glance, you may think that cockroach droppings are mouse droppings. After all, both of these pests inhabit similar areas and have poop similar in size and color. However, you can tell them apart because mouse poop:
- Is larger in size. It’s about 3 to 6 millimeters vs. 2 millimeters.
- Looks like pellets. Cockroach poop looks like coffee or pepper grounds.
- Pointed ends. Mouse droppings are pointed on the ends, while roach feces aren’t.
- Longer. Mouse feces are thin and long.
American cockroach poop can trigger asthma attacks. It also carries harmful bacteria that cause diarrhea, sickness, and infections.
How Do American Cockroaches Reproduce?
Usually, cockroaches reproduce sexually. One adult female cockroach can produce up to 224 offspring during her lifespan. This begins when a male and female engage in mating behavior.
During courtship, females raise their wings and expose their internal membranes. They then expand their genital chambers and releases pheromones that attract males. This is called the calling position. Interested males approach females by flapping their wings to show they’re interested. The male will then back into the female and deposit its sperm.
After breeding and subsequent fertilization, the female will produce an egg sac, which she attaches to a flat surface. This will be somewhere in her environment, near a source of food. The spot must be secluded, damp, and preferably dark.
After about 24-38 days, the eggs will hatch into nymphs. These baby cockroaches will fend for themselves and immediately seek out food. At this stage, the nymphs are 1/4-inch long and are grey-brown.
As they grow, they will undergo several molts. This allows the cockroaches to shed their old exoskeleton and form a new one. By doing so, they grow in size and develop their wings. They will briefly turn white as the new skin tans itself into the classic brown color. After about 600 days and around 10-13 molts, the cockroach will officially reach maturity.
Do American Cockroaches Reproduce Asexually?
While sexual reproduction is the main route for American cockroaches, they can also reproduce asexually. On average, this happens when a colony is mostly composed of females in a dense group. Without enough males, the cockroaches can develop their own way of keeping the species alive.
According to Hokkaido University, females can produce eggs by parthenogenesis. This means the female creates offspring from an ovum without fertilization. The nymphs grow from the maternal egg, so they are always female but can survive and produce offspring themselves.
They live for approximately 30 months. In 15 months, the new females start breeding. Females create two egg cases, containing around 16 eggs, at the height of their reproductive capabilities. After that, their reproductive ability decreases to approximately one per month.
Are American Cockroaches As Bad As German Cockroaches?
German cockroaches are the more common species of the two. Because of that, they’re considered the worst type of cockroach to infest a home.
Their populations can grow quickly since German cockroach females produce 30-40 eggs in each ootheca. In contrast, American cockroaches only produce 16-18.
American cockroaches may be larger, but German cockroaches use their tiny size to wiggle into smaller hiding places. This can make them harder to uncover and more difficult to get rid of. American cockroaches live in warm, damp environments, such as storm drains and sewers. German cockroaches are far more likely to live in man-made structures and appear more frequently in the open than the American kind.
However, both harbor harmful bacteria and pathogens that cause nasty infections and diseases. Both American and German cockroaches:
- Trigger asthma and allergies
- Create unpleasant odors around the home
- Walk through bacteria-ridden environments
While German cockroaches may be more likely to cause a nuisance in your home, they’re both as bad as each other once they get in.
Do American Cockroaches Bite?
American cockroaches do not bite. According to the University of Cambridge’s Department of Zoology, their mouthparts cannot pierce human skin. They have a robust mandible that allows them to bite, but it mostly pinches the surface. Cockroaches have no desire to bite humans but are happy to eat organic waste. This may include:
- Dead skin flakes
- Fingernail clippings
If a cockroach is starving and has no other options, it may crawl on you during the night. If it thinks it can consume dead skin or any crumbs left around your mouth, it may try to bite. This won’t pierce the skin, but the little nibble can result in:
- Minor infections
This will be due to the bacteria that cockroaches leave behind. American cockroaches are not venomous.
Where Do American Cockroaches Hide?
American cockroaches prefer warm, damp environments that offer easy access to food and water. Their favorite places will include:
- Leaf piles
- Compost piles
- In sheds or around the foundation of your home
- Sewers or drains
You’re more likely to see them inside during winter when the weather gets cold and they run out of food. Here, they will come into your home. Once inside, their favorite hiding places include:
- Near garbage
- Around sump pumps
- In garages, especially in or around storage boxes
- In dark basements
- In crawl spaces
- In floor drains
- Behind appliances like freezers, fridges, and washing machines
- Under or around bathtubs
Instead of small cracks and crevices, like most cockroaches, American cockroaches will gather in open spaces. This makes your basement, crawl space, or garage their main target. They will have ample room to explore for food without being disturbed.
How Do American Cockroaches Get Into Homes?
Of course, if you find cockroaches hiding in these places, you may be confused about how they got there. They can’t tunnel through wood, like termites, but they’re even more insidious. They gain access from:
Cardboard And Newspaper
Paper attracts cockroaches. It’s organic material that’s easy to chew through, gets damp and moist, and is found in hiding places American cockroaches like. As such, if you recently brought several storage boxes inside, cockroaches may have hitched a ride. Old newspapers or packing materials are also a danger.
Cracks In The Foundation And Exterior Walls
American cockroaches can fit through gaps as narrow as 1/16 of an inch deep, regardless of their size. Cockroaches can get into spaces over 1/2 their size. They flatten their exoskeletons and splay their legs out to the side to make themselves as agile as possible. Any holes are an open invitation for cockroaches in a building’s foundation or exterior walls. Any space around pipes, windows, and vents can also be used as an entry point.
Cockroaches may come through drains and pipes, especially if they lived in the sewer. This is particularly true for apartments, where much of the plumbing is shared. This enables them to transfer from one unit to the next.
Apparel And Luggage
American cockroaches stow themselves away on paper food bags, briefcases, purses, backpacks, and other unsuspecting personal objects. If they lay their eggs inside one of these things, an infestation can easily take hold within your home.
For cockroaches, this is the most common point of entry. The light draws them from outside, and any small gap is enough for them to pass through.
American cockroaches love to hide in woodpiles. Since they typically inhabit forested areas, they may come in on any firewood deliveries or be carried from your yard’s woodpile.
Dry Food For Pets
Since American cockroaches are excellent scavengers, they’ll see pet food as a free meal. If you feed your dog or cat outside or leave extra bags of food in the garage, they may come indoors that way.
What Attracts American Cockroaches?
American cockroaches have basic requirements consisting of:
They’ll set up home wherever they find these vital things to survive. American cockroaches are attracted to warm and safe environments. They thrive in temperatures of around 84 degrees Fahrenheit. If the weather turns cold outdoors, you will find them seeking out your home. At overly high temperatures, at around 100 degrees or more, they will also crave your air conditioning.
Aside from that, cockroaches need a constant food supply. They will be drawn to any leftovers, crumps, or spills around your home. Even failing to empty your bathroom’s trash can will attract them. American cockroaches will eat hair, skin flakes, toothpaste, and even soap residue.
Leaky pipes or condensation from around your bathroom are great lures. American cockroaches will take up residence in your basement, under your sink, or in your bathroom. As long as it’s damp, they’re happy. Because of this, look for these bugs in:
- Small spaces
- Pantries that are stocked with food
- Unkempt areas of the home
- Sinks and dishwashers full of dirty dishes
- Corners that haven’t been swept or vacuumed often
What Repels American Cockroaches?
Insecticides are designed to kill cockroaches, not ward them off. You can deter cockroaches from certain areas with household solutions while you apply extermination methods. Here are a range of essential oils that American cockroaches dislike:
In general, cockroaches dislike the scent and taste of peppermint. In fact, in concentrated amounts, it can even be toxic to them. Prolonged exposure to peppermint oil will eventually kill them.
To effectively repel American cockroaches, dilute a few drops of peppermint oil with water and soak cotton balls in the solution. Place these in areas where the cockroaches should be deterred. You can also spray the solution around your home using a water bottle. Be careful of other pets, though, as they also may not like the smell.
Tea Tree Oil
This is a natural repellent for insects that cockroaches dislike. Mix this with 2 parts of water and spray it into cracks and crevices to keep cockroaches away. For a stronger mix, combine the solution with vinegar.
Citrus Essential Oil
Citrus oil has a heavy odor, and most cockroaches despise the smell. That’s why many insecticide sprays have a mild orange scent. Mix 1 liter of water with a few drops and spray in all corners of the home. You can also try leaving dried orange peels where you believe cockroaches to be lurking.
According to the same study as we previously mentioned, oregano oil is the most effective cockroach repellent with a success rate of between 96.5–9.1% at a concertation range of 2.5–30%. While it’s not been proven to be toxic, it does an excellent job of keeping cockroaches away. It also has a residual effect of one week after treatment.
Eucalyptus Essential Oil
Thanks to the potent odor, eucalyptus oil confuses and alarms cockroaches. It also has a 36.2% mortality rate when cockroaches are exposed to the oil. Mix it with 2 parts water and mist corners of our bathroom, kitchen, and garage.
Rosemary Essential Oil
According to a study by the Journal of Arthropod-Borne Diseases, rosemary oil delivered a 100% mortality rate at a 2.5% concentration, deeming it an effective method of cockroach pest control as well as a repellent.
How To Get Rid Of American Cockroaches
No matter how effectively you repel American cockroaches, they are persistent. The only way to keep your home safe is to completely eradicate their nest and colony. Patience and a combination of both chemical and non-chemical techniques are needed. Here’s how to start:
For smaller colonies, you can use insecticide spray on any cockroaches you spot. Depending on the brand and the formulation, the cockroaches may not die right away. Instead, this will paralyze the cockroaches and cause them to starve over time.
Set Out Bait
The best approach is to pair insecticide spray with bait traps. These traps are made up of food that’s laced with poison.
Once the cockroach ingests the bait, it will return to its nest and spread the poison around through its feces. After it dies, other cockroaches will also eat the body and consume the poison. This can help kill off an entire nest over a few weeks.
Cockroaches will be forced to move on if they cannot locate food or water. To minimize their options, be sure to tidy up your home. Cockroaches can survive even in a spotless apartment or house, but they will find it more difficult.
- Wipe up spills
- Wash dishes
- Clear away garbage
- Don’t leave pet food in a dish
- Regularly sweep
- Vacuum at least once a week
- De-clutter areas that cockroaches can hide behind
To cut off the water supply to an American cockroach nest, be sure to patch any leaky pipes and seal any unused drains. Likewise, seal up any gaps in your windows, doors, or home’s skirting. If the cockroaches can’t get in and out, they’ll be forced to eat your bait.
You can use boric acid around key areas in your home that cockroaches visit. Sprinkle it in corners, around appliances, and near places where food is kept. This protective barrier will kill off the cockroaches that encounter it.
Diatomaceous earth is a natural, sand-like powder made from the fossilized atoms of aquatic organisms. Food-grade diatomaceous earth is safe to use around pets and children but effectively kills cockroaches by scratching the surface of the exoskeleton, drawing out essential fats, liquids, and oils. It will go on living for a short while, but it won’t be able to absorb nutrients and will eventually dehydrate to death.
American cockroaches have long lifespans and are the biggest of their kind. To keep them out of your home, be vigilant about how they gain access, and be sure to remove any of the things that attract them inside.