Why Do Cockroaches Exist?

Couple of frogs on a log staring at a roach

Cockroaches look like purposeless creatures, especially when they have taken over your home. They spread diseases, contaminate food and water, and even send shivers down your spine by standing right beside you at night.

Having that bad reputation, you must be wondering: “Why do cockroaches exist?” They keep our ecosystem intact, provide food sources to humans and insects, offer sustainable fertilizers, and much more.

Let’s learn about why cockroaches exist and their role on this planet.

Why Do Cockroaches Even Exist?

Cockroaches exist to serve the ecosystem by recycling organic decay and providing nitrogen to the soil. They are also food to many animals and insects, including:

  • Lizards
  • Frogs
  • Rats
  • Geckos

Although you consider them only pests, they play an important role in the wildlife.

Cockroaches help nature rebuild itself. There are over 4,000 species of roaches, of which only 40 are considered pests. The remaining species, which comprises almost 99.7% of their population, live in their natural habitat, away from humans.

Actually, cockroaches are more comfortable living in their natural abode. They didn’t want to interfere in our lives until we chose to expand due to the increasing population.

So, it was us who interfered with the cockroaches, not them.

How Cockroaches Help Nature?

Cockroaches help nature in different ways. After all, nothing in this universe exists without a purpose. The 4 ways are:

Food for Birds and Mammals

There are places in the world where many birds and insectivorous mammals (who eat insects) feed on dead and alive cockroaches. In fact, roaches are more than 50% of the food for the endangered red-cockaded woodpecker. You might never see such a beautiful woodpecker again if there were no roaches.

Cockroaches are a suitable meal for many mammals, amphibians, and reptiles. Even rodents like rats and mice also eat cockroaches.

Food for Insects

Cockroaches are common food for other insects like:

  • Geckos
  • Lizards
  • Wasps

Usually, these insects eat dead cockroaches.

When you set a poisonous trap for cockroaches, they become intoxicated and flip on their backs. That’s when they are most vulnerable and become prey to other pests.

You might also have seen the roach’s body parts scattered in your home. That usually happens when insects eat their dead bodies and leave the remains behind.

In fact, the emerald cockroach’s (aka jewel wasp) survival depends on roaches. Some wasps like dead cockroaches, while others look for them and hunt them down.

How Do Jewel Wasps Depend on Cockroaches?

The jewel wasp stings a cockroach and enslaves it. The wasp’s sting contains a mind-controlling venom that disables the neural activity inside the roach’s brain.

After the sting, the roach gradually loses control of its behavioral response to fear and emergency. That’s why it doesn’t flee when the wasp leaves it to find a suitable burrow for the baby wasp.

It’s the instinct of an emerald or jewel wasp to turn a cockroach into a zombie. Since the roach lives after the sting but doesn’t run away, it becomes the food for the wasp’s larva. That’s how the baby jewel wasps are born, and the cycle continues.

Nitrogen Cycle

These so-called disgusting creatures can eat almost anything. Roaches consume and digest stuff unwanted by other animals and give nitrogen back to the soil, thanks to their excretory system.

Most bugs eat decaying organic material like dead leaves and animal manure. However, such an act is disgusting yet beneficial for the environment.

The digestive system of cockroaches can quickly decompose the decaying organic stuff. Once they digest it completely, they excrete and give nitrogen to the earth.

Therefore, the cockroaches’ poop is a vital sustainability factor for the forests.


Entomologists discovered that a species of cockroaches, moluchia brevipennis, feed on pollen grains. So don’t be surprised the next time you see roaches moving from one flower to another in search of food.

The legs of these pests get pollen from the flower. Then, when they move, they transfer the grains from one flower to another, becoming a pollinator.

Other species of cockroaches can also become pollinators if they start living in flower beds rather than in the dark corners of our houses.

Are Cockroaches Afraid of Light?

Cockroaches are not exactly afraid of the light; they just don’t like being exposed to it. So they either run away or fly to a safer, darker place when you turn on the switch.

Almost every species of cockroaches are nocturnal, which means they are most active at night. This is why when you brighten up the room, you see how quickly they run for a darker shelter.

If somehow you spot a roach in the daylight, there must be a sound reason behind that.

  • Hunger. A roach leaves the dark corner usually due to starvation. So if you see one cockroach coming out in broad daylight, prepare yourself because a whole gang might also be coming out in search of food.
  • High Adaptability. If you have been hosting cockroaches for a long time and giving them almost no dark space to live, they might get used to living in the light. Cockroaches can adapt to environmental changes and can adjust with light.

Spotting a cockroach in the daytime is good as you become aware of the infestation. If you spot more than two of these bugs, you must understand that there could be a whole army behind that cabinet door or the refrigerator.

The population of cockroaches spread at a fast pace. For example, the German cockroach reproduces 300 young ones in one year.

What if Cockroaches Became Extinct?

If cockroaches became extinct, there would be a disbalance in the ecosystem. Yes, they are the reason behind many infectious diseases, but they are a food source for many insects. In fact, a species of wasp relies on roaches. So their extinction means those wasps will no longer survive as well.

Moreover, forests would suffer without cockroaches. More than 97% of the roach’s population lives in jungles and feeds on decaying organic material. Until now, no other creature eats that stuff.

Since only cockroaches can digest that material, they can reproduce nitrogen by excreting it. That’s how the trees and plants in the forest fulfill their nitrogenous needs.

Would There Be Enough Oxygen in the World Without Cockroaches?

There might be enough oxygen in the world without cockroaches because of scientific evolution. However, the natural lifestyle of forests and animals may face the consequences of having no roaches around.

Since these insects play a vital role in nutritional recycling, the soil might never get enough nitrogen without the help of cockroaches. As a result, trees and plants may begin to die.

Humans can undoubtedly find a way to produce oxygen through different methods. But the wildlife might face life-threatening danger due to the extinction of cockroaches.

How Are Cockroaches Useful to Humans?

Cockroaches are helpful to humans in many ways. These pests do more than wander around in the dirty little corners of your house. You might plan to crush them whenever you spot one, but your perspective might change once you know how beneficial cockroaches are to humans.


You can find how profound cockroaches are in Asian dine-ins and buffets. Not only in Asia, but people in the USA, China, Brazil, Mexico, Netherlands, and Ghana also don’t hesitate to eat these pests.

Although cockroaches are too gross to eat, their bodies have:

  • Protein
  • Fat
  • Crude ash
  • Carbohydrates

Moreover, a rare species of cockroach produces milk in crystalline protein form. The female cockroach gives birth to its babies like mammals instead of laying eggs. That cockroach milk is the source of food for the baby roach.

Those protein crystals of milk have high nutritional value. Who knows; you may soon see a cockroach milk sample in your supermarket’s dairy food section.

Insect Feeder

Many insectivores feed on cockroaches to fill their bellies. These include:

  • Hornets
  • Lizards
  • Frogs

There are farms to grow Dubia roaches to feed these insects and animals.

But why only Dubia cockroaches? It’s because this species is slower than other cockroaches. So you can easily spot and take out one without a second attempt. Also, it’s easier to raise its generation than other roaches.


Cockroaches have medical uses as well, especially in today’s Chinese clinics. For example, doctors ground up cockroaches to treat ulcers. Many researchers are also studying how these pests can serve in the medical industry.

The roach’s brain is also under consideration to fight bacteria like E Coli. During an experiment, the bacteria instantly died when it reached the roach’s brain cells and nerves.

This proves that cockroaches are helpful in the pharmaceutical industry to treat several diseases. But there’s still time for such medicine in the pharmacies.

How Do Cockroaches Live?

Cockroaches live in the dark corners of your house. Since they don’t get along with light, they prefer hiding until the night casts its shadow. These bugs are not hunters, and they are also harmless to humans.

You might see roaches being the most active at night once they start living in your house. They do so to:

  • Come out from the dark corners in search of food
  • Wander around the refrigerator
  • Run on or under the sink

Primarily, these creatures search for food at night. They can feed on almost anything, even if it’s not edible to other pests. That’s why you will always see them moving around the zones where they can most likely find something to eat.

Do Cockroaches Live in Colonies?

Cockroaches live in colonies built close to food and water. Their territories differ from ants but share a sense of family. This is the main reason you never see roaches living and crawling alone. Instead, they prefer living and reproducing in groups or colonies.

Although exploring a roach colony is gruesome, you can still give it a try for experimental purposes. Cockroaches create colonies to:

  • Find shelter
  • Lay eggs
  • Hide from daylight and humans

You may be wrong if you expect a roach colony to be an organized little bedroom. Instead, a cockroach colony is a messy playroom where everything seems to be in chaos.

When you discover their abode, you will find cockroach feces, eggs, wings, and even corpses scattered here and there.

Therefore, if you are sensitive to such sickening exploration, avoid messing with the colony. Instead, contact a professional fumigation service and get rid of roaches once and for all.

How Have Cockroaches Survived for Centuries?

Cockroaches are disgusting yet intelligent creatures with a strong defense system. They use several tactics to dodge their hunters and escape the ambush. Wild roach species are more professional in defending themselves than house roaches.

Many wild roaches species can:

  • Change Color. Wild cockroaches can change their color. This ability camouflages them and saves them from a threat.
  • Hiss. Cockroaches can make a hissing noise when they face any kind of danger. Of course, you might never hear this sound because they run or fly away within a blink of an eye. But if you confine them in a vulnerable space, you might get to listen to the roach’s hissing.
  • Fly. A flying cockroach looks more deadly but is still harmless to humans. A roach might spread its wings and try to reach a safer spot as quickly as possible when there’s lurking danger on the ground.
  • Spray Chemicals. A wild beetle category of cockroaches can become aggressive and spray a chemical. This chemical has an extremely foul odor that repels other insects, birds, and animals away.

Do Cockroaches Migrate for Their Survival?

Cockroaches migrate from your home to the neighborhood whenever they sense danger. It primarily happens when you or your neighbors fumigate their homes. However, they may also migrate when the babies become adults and don’t have enough space to live and settle.

Cockroaches build colonies in places that have:

  • Food Nearby. Cockroaches can survive for a month without food. This is because they are cold-blooded insects and quickly adapt to changes. Moreover, they reduce their functions to only basics whenever they don’t find anything to eat.
  • Water. A cockroach can survive without its head but will die in a week due to thirst. Sounds interesting, isn’t it? The insides of a cockroach need water to function correctly.
  • Shelter – Like every living creature, cockroaches protect themselves and their colony from danger. That’s why they always look for a safer, darker hiding place.

Are Cockroaches Pests?

Not all species of cockroaches are pests. Although we encounter them in our homes and backyards, they serve a bigger purpose in this world.

There are only four species of cockroaches that we see wandering around. More than 4,000 other species live in the wild without human intervention. They don’t like to interfere with our lives because that’s not their real purpose.

Those species live in:

  • Forests
  • Streambeds
  • Mountains

When the human population wasn’t that large, cockroaches were never considered pests. They used to play their role in the ecosystem without disturbing anyone.

But when the human population increased, we began invading the roach colonies and building homes there. Whenever you try to steal someone’s natural habitat, they opt for one of the two options:

  • Run for another shelter
  • Hide in the soil

Cockroaches found the former more suitable and hid there until hunger and thirst forced them out. That’s how we met cockroaches when we built homes on their lands.

Besides, some species of these so-called pests are endangered. However, you might not have seen them because of the global changes that affected these insects’ generations.

Should We Kill Cockroaches?

You should kill cockroaches as they carry disease-causing bacteria, allergens, and molds. When these bugs enter your home, they start crawling everywhere, spreading germs all along. Thus, the presence of roaches in your home can pose a major health threat to your family.

You should kill cockroaches as soon as you see one or two roaming in your home. Undoubtedly, cockroaches are incredible survivors. What more can you expect from a bug which can live without its head?

But remember to eliminate these bugs correctly, or the situation may worsen. That’s because a dead cockroach attracts other bugs towards itself by releasing oleic acid, the “Death Stench.”

Oleic acid is fatty, making it a good food source for bugs like roaches. When a cockroach dies, the pungent smell of this acid alerts other comrades that one of them is down.

But since it’s the survival of the fittest, all cockroaches gather around their late member, and instead of paying tribute, they devour it. Therefore, killing a cockroach might not be a good idea.

Instead, use some remedies like:

  • Use insecticides that can kill roaches in large quantities.
  • Kill their water supply.
  • Keep your house clean.
  • Check for wall cracks and door and window openings and fill them.


Should You Protect Cockroaches?

You should not protect cockroaches because they can spread diseases in your home. They are also not useful for scientific experiments because scientists already have many species in the labs. So protecting roaches is not a good idea.

Is there Anything Good About Cockroaches?

There are several good things about cockroaches, such as:

  • They eat almost anything, including decaying organic material. As a result, they give nitrogen back to the soil.
  • Cockroaches are a feed for many other pests, birds, and mammals. They keep a balance in the ecosystem.
  • They transfer pollen grains from one flower to another, keeping the environment colorful.

Will Cockroaches Ever Go Extinct?

Cockroaches aren’t going extinct anytime soon. They were on this planet millions of years ago, and more than 90% of their species is still untouched by human intervention.


Thinking that cockroaches are useless pests might be wrong. They exist for multiple reasons, including:

  • Recycling nitrogen for the trees, especially in the forest. That’s a major sustainable factor for wildlife.
  • Many birds, mammals, and even insects feed on cockroaches.
  • Emerald or jewel wasp’s life cycle entirely depends on roaches.
  • A significant source of pollination

If your home has a vast roach problem, you must eliminate it as soon as possible. But remember to follow the safety steps mentioned above to make your home roach-free more quickly and effectively.