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Hey there!  welcome to the new episode of Curiosity! after a long time. Finally!

Yes , Cockroaches have bad reputation around the world. They are considered creepy , gross and yuuuuck ! but what you might not know is they are way cooler than you might think. No matter what we do to get rid of these evolutionary beings , they are always one step ahead of us. As the matter of the fact there are more  than 4500 species scattered around the world. Yes they can literally eat anything organic and poop anywhere but its actually beneficial to the environment. How cool is that? I know not that much but wait hang on with me. 

Cockroaches Can survive the nuclear fallout or in simple word radiation and they can pretty much live for a week without the damn head. That might sound like a science fiction. Well, lets get to the details now. how much of the truth is in above sentence. Lets get started.

First Part - Surviving the Radiation.

How did this idea of cockroaches surviving the nuclear radiation emerged in the first place? Well, after the nuclear attack on Hiroshima and Nagasaki, it was reported that cockroaches were the only survivors. 

Lets get to facts now. To know the truth behind this topic, Myth-busters actually conducted an experiment. The subject cockroaches were exposed to different levels of radiations. The First level was 1000 rads which can kill a normal human in just about 10 minutes. Second level was 10,000 rads (approximately the radiation generated in the bombings). Finally the third level was 100,000 rads. They were observed for about a month.

Fig: Myth busters Report (Source)

The results were just unbelievable. 50% survived from 1000 rads group which can kill a human probably in 10 minutes. About 30% survived from 10,000 rads group and none of them passed through 100,000 rads group which is just insane amount of radiation. The only thing that survived this insane level of radiation is Flour beetles.

But how is this possible? are they immortal?

They are not really immortal. Of course they have to die at some point. This is simply possible because of their simple body design and the slower metabolism and cell division. Comparing to a human, our cells are constantly undergoing division. In fact some of our cells are replaced only in the matter of few days. But in the cockroaches, their cells only divides when they are in the stage of molting. Cells are mostly damaged by radiation when they are in their dividing stage because the damaged DNA is passed on. This is not the case with cockroaches, their cells are not constantly dividing and yay! the 50% of the cockroaches that died in 1000 rads group were in their molting stage. They only molt once a week.

Fig : Cockroach molting (Source)

So yes, they can definitely survive the radiation that can kill humans in minutes but it's impossible to survive the heat from the nuclear explosions.

Second Part - Decapitation

 Can a cockroach survive without its head, Yup! they can but only for some weeks. The real question here is how can they do that? and why only for some weeks?

Again the answer lies within their simple body structure. Not only cockroaches but many other insects can live for week after decapitation. To understand this, lets compare this idea with ourselves. Any human would die in the matter of seconds because of various reasons, i.e Extreme blood loss, drop in the blood pressure, since their in no brain the breathing and all the vital functions will immediately stop and much more which will lead to death in seconds.

Fig: Open Circulatory System (Source)

Cockroaches have much simpler body design. They have a very minimum blood pressure because of their open circulatory system. This basically means the blood is pumped directly to the different body cavities. There is no need of complex network of capillaries like we humans do. When they are decapitated, the blood just rapidly clots around that area. NO BLEEDING = NO DEATH FROM BLEEDING.

What about respiration then?

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Well, the brain is not in charge for the control of breathing in these type of insects. These insects breathes through the little holes called spiracles. Spiracles are found scattered through out the body. Also the blood doesn't carry the oxygen, these spiracles directly sends air to the tissues and different organs. So yup! they can even breath normally without their head.

Can they react to things when decapitated?

These type of insects have nerve ganglia all over the body or on each segments. These ganglia are responsible for different reactions and reflexes separately. So even without the damn head they can move, react and stand. How cool is that?

but Wait what about the food?

This is the part where things get serious for a decapitated cockroach. Since they are cold blooded, they don't generally need much food to survive. Eating just one day they can survive for weeks. But finally they die from thirst and starvation after some weeks.

Finally, even if cockroaches can survive through a lot, they have to die at one point. They are not immortal. But still this makes it one of strongest insects on Earth.

 Well, thats it for this Episode. Hope you Enjoyed it , if you did Upvote and comment your thoughts below. Thank you!!

Stay Curious. 

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 References used:

[1]-  Cockroaches in Nuclear Explosion

[2]-  Cockroach without head

[3]- Myth Busters Experiment Video

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