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Can a Cockroach Live without Its Head?

Last Updated: 27.09.20


Cockroaches are difficult to get rid of – if you want the best solution that you can use against them check it out here. As some of the oldest insects that have walked the Earth, roaches have survived because of their ability to adapt. For instance, these critters can live a week without their heads, they are incredibly fast and they can hold their breath for 40 minutes underwater.


Is it fact or fiction?

You have probably heard the claim that a cockroach can live without its head. The question that arises is whether this statement is based on facts or just fiction. According to the specialists, this claim is based on demonstrated facts.

Roaches are known as adaptable pests that can most likely survive a nuclear war. Therefore, it should come as no surprise that these pests can, indeed, survive without their heads for around a week.


How is this possible?

To understand why roaches can survive decapitation, and why humans cannot, we must take a closer look at the differences in anatomy. First things first, when decapitated, humans lose a lot of blood. When the body has little to no blood, oxygen can no longer get to the vital tissues.

On top of that, humans use their noses and mouths to breathe. Whenever the brain cannot control these organs, breathing stops. Lastly, without its head, a human cannot eat, and, therefore, it cannot survive.

On the other hand, the anatomy of a cockroach is very much different than that of a human being. To start, roaches do not have blood. So, whenever their heads get severed, they do not lose blood pressure. When the head of a roach is cut, the immediate reaction that can be observed is that the neck of the insect closes off.

Another thing that you should know is that the brain of the roach does not control its breathing. The body of an insect of this sort does not use blood to carry the much-needed oxygen through its body. Instead, cockroaches have spiracles that take air directly to the tissues by using several tubes known as tracheae. 

Another factor that enables roaches to survive decapitation is the fact that they are cold-blooded critters. This means that they do not need as much food as humans do to survive. A cockroach can survive for weeks without eating.

Because roaches have nerve tissue agglomerations that are distributed throughout their body segments that can perform basic nervous functions, the body of a roach can manage without the brain. By this, we mean that they can still have basic reactions. For instance, even without a brain, a roach can stand and move.

Not only the body survives the decapitation process. As researchers have shown, the decapitated head of a roach also survives the cutting. For hours after the separation, the antennae on the head of the roach can still move. The separated head can function even longer provided that it is placed in a cool environment such as a refrigerator. 

The reason why roaches die after their head is separated is because they cannot survive indefinitely without water. So, in the end, they die due to dehydration.



How it all started

Even if it might seem cruel, scientists have started to decapitate and analyze roaches almost sixty years ago. In 1962, a well-known neurobiologist called George Adrian Horridge was the first to publish the results of his research. In his experiments, he would hold roaches over a saline mixture that was used to deliver a shock to one of the legs of the insect.

After the experiment was repeated time and time again, even when decapitated, the roach knew to keep its leg raised so that it wouldn’t receive a shock.

Another researcher, Roy Ritzmann has also taken a close look at headless roaches. He discovered that these insects need their brain stem-like structure in order to walk properly. Therefore, he noticed that the roaches that had their spinal cord ruptured could walk somewhat normally. However, they were unable to stop. In other words, they would walk forever.

Throughout their research, these specialists have also observed that, when decapitated, cockroaches were easier to analyze closely as they did not try to run. Let’s not forget, under normal circumstances roaches can move very fast. 


The results

Studies on decapitated roaches have helped researchers to understand the metamorphosis and the reproduction cycle of the insects. On top of that, these studies have also been a way for professionals to understand how the neurons of these pests work.

As the results that we have talked about have shown, even if headless roaches are not the smartest of the bunch, they are, however, likely to survive. This is something that we cannot say about humans, cats or dogs.


Other weird, yet fascinating facts about roaches

Cockroaches are some of the most adaptable insects that have ever walked the Earth. Here you can find some weird, yet fascinating facts about these pests.


They can hold their breath

Differently from what you might think, roaches do not breathe through their mouths. Instead, they use an opening in their thorax. Once the oxygen enters the opening, a complex system of tubes transports it throughout the body of the insect.

Another unbelievable thing about roaches is that they can hold their breath when there is not enough air. One study from 2009 has demonstrated that roaches can hold their breath for several minutes when the oxygen level is low. Roaches are also known for holding their breath as a way of saving water.

It seems like, in low humidity environments, these insects can hold their breath even longer. The researchers have interpreted this as a way in which the roaches adjust their behavior to the conditions that they have to face. Roaches are among the very few critters that can do this.

Most species of cockroaches like living near a water source. Still, not many species can survive in water for a long time. This mainly happens because roaches cannot swim. Instead, they just float from one place to another.

However, it should be said that most of these pests can, according to scientists, survive to up to 40 minutes when they are submerged in water. So, drawing a roach is more time-consuming than you might think.



They can live for a month without food

As we have pointed out before, roaches are highly adaptive critters that can handle difficult conditions. According to research, these insects can survive a month without eating. Although they can physically do so, most roaches are not likely to reach the one-month benchmark if they are not provided with a source of water.

If they have no access to water, cockroaches start showing signs of dehydration and they die in about one week. As a way to get rid of roaches, some people often use Diatomaceous earth, an abrasive powder that gets through the exoskeleton of the roach and it absorbs all the water from the body of the insect.


They are very, very old

It has been proven that roaches are some of the oldest insects that are currently walking the Earth. The fossils that have been discovered demonstrate that these critters used to exist 280 million years ago. To put this piece of info into perspective, this means that these insects used to live even before the dinosaurs were around.

The Carboniferous era was the era of the roach. Back then, these insects had few predators and they were some of the most advanced critters out there. Even then, roaches used to rule the entire planet. The numerous cockroach fossils that were discovered all around the world seem to prove this point of view.

The reason why cockroaches still live and, may we say, thrive today has to do with their ability to reproduce fast. What is more, some species can also reproduce without needing a mate. This form of asexual reproduction is called parthenogenesis.

The American cockroach, one of the most common pests in American households can multiply through parthenogenesis. A study from Japan has shown that a colony of 15 virgin female roaches were able to reproduce and survive without a male roach for up to three years. 

Finally, roaches are some of the fastest insects out there, as a cockroach can travel faster than a cheetah. 



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