Why Do Cockroaches Move When Dead?

If you’ve ever killed a roach, you may have noticed it move around after it died. 

And you may be wondering, how on earth do they do that?

Cockroaches sometimes move when they are dead or about to die because their muscles involuntarily contract at the time of death. Typically, you will see this movement in their legs. Roaches may also flip onto their backs when they die since they are top-heavy. Yet, roaches don’t move when they are completely dead. 

Why Do Roaches Move When They’re Dead?

You may see a roach move while they are dying or sometimes in the seconds after they have died. 

In general, though, if you see a roach still moving, it is not dead or at least not dead yet. 

You may believe it should be dead, though, which will give you the impression that it is moving long after it has died. 

For example, if you spray a roach with insecticide, you may expect it to die immediately. 

However, even if you spray a roach directly, it will not die instantly. 

Instead, it takes some time for the roach to die, and they may even keep running after you spray them. 

Or, they might flop onto their backs and kick their legs. 

Thus, if you expect the roach to die instantly, it may appear that it is moving after death, but this is not so. 

Additionally, remember that most insect sprays work on the nervous system, which causes involuntary muscle spasms. 

Therefore, if you just sprayed a roach, and it is writhing around, you are likely just seeing the effects of its nervous system failing. 

But, a cockroach technically can move for a few seconds after death because when a roach dies, its legs curl inward towards its torso. 

And since roaches have fat bodies supported by thin legs, they are quite top-heavy, causing them to flip over onto their backs when their legs curl. 

If a Roach Is Moving, Is it Still Alive?

If a cockroach is moving, it is most likely still alive. 

Usually, at the time of death, the roach will already be completely still or will only move around for just a few seconds longer. 

Do Cockroaches Play Dead?

Yes, cockroaches can play dead. 

Typically, roaches play dead when they detect a threat. 

So, for instance, if you hit them with a newspaper, they may roll on their backs and stop moving. 

Or, if your cat is playing with a cockroach, it may act as though it is dead. 

Roaches do this because they want you to believe they are dead in the hopes that you will leave them alone or just throw them in the trash can, so they can later get up and return to their nests. 

Sometimes, though, the roach can not control its instinct to play dead. 

This phenomenon is an issue because people often check to ensure a roach is dead by poking it to see if it moves. 

However, if the playing dead reflex is involuntary, the cockroach won’t move because it literally can not. 

Thus, if you see a roach that is not moving and appears to be dead, you should take action to ensure it has truly died before disposing of it. 

The best way to make sure the roach is dead is to step on it until its torso pops open. 

Or, if you don’t want to do this, you can always spray it with a roach spray instead. 

Can Cockroaches Live Without a Head?

Yes, cockroaches can live for about a week without a head. 

They can survive without a head partly because they do not solely rely on their brains to control their movements. 

Unlike humans and many other animals who depend completely on their brains to move, roaches have nerve tissues throughout their bodies that control muscle reflexes. 

Additionally, a headless roach will not suffocate to death because cockroaches do not breathe with their mouths or noses. 

Rather, they respire through tiny holes along their bodies, and they don’t need a brain to control this reflex either. 

Furthermore, a headless cockroach will not bleed to death as a human would without a head since they don’t have blood pressure in the same way that we do. 

Roaches have an open circulatory system, meaning they do not have veins and blood vessels that carry blood around their bodies. 

Instead, their blood just sloshes around inside them to lubricate their organs. 

And because their blood doesn’t need to move through veins, they don’t really have blood pressure. 

So, when their heads come off, there is no pressure that shoots the blood out and causes them to bleed to death. 

Their blood just clots around their necks and creates a plug. 

All of these things allow a roach to move around and continue its life without a head. 

However, headless roaches can not eat or drink, causing them to die of dehydration, typically within a few days. 

Read Also > Can A Cockroach Survive Being Cut In Half?

Why Do Roaches Die in the Middle of the Floor?

Researchers do not entirely understand why roaches often die in the middle of a room instead of in a hiding place, as most animals do. 

But, one theory proposes that roaches that come into contact with insecticide die out in the open because the poison in the pesticide makes them confused. 

Another reason you may find dead roaches in the middle of the floor or counter is that cockroaches typically have a hard time getting off their backs without something to assist them. 

Thus, if a roach gets flipped over in the middle of a smooth floor or countertop, it may not be able to get back up and will eventually die. 

Roaches don’t normally have this problem in the wild because there are usually sticks or something else around that they can use to right themselves. 

Yet, when everything near them is smooth, they might just struggle without success until they become exhausted and perish. 

Can Roaches Come Back to Life?

No, a cockroach can not come back to life. 

Just like other animals, when they’re dead, they’re dead. 

But, since they can play dead so well, it may seem that they have come back to life when, really, they have simply stopped pretending. 

Can Cockroaches Feel Pain?

When it comes to smashing or spraying bugs, especially when they are writhing around, many of us wonder if they can feel pain. 

And, of course, the answer isn’t straightforward because no human has ever been inside the mind and body of a cockroach to say for sure what they feel. 

However, as far as researchers can tell, roaches do not feel pain. 

Cockroaches do not have the same pain receptors that humans and many other animals have. 

Thus, they can not feel the type of pain that we do when we are hurt. 

But, entomologists are almost certain that roaches know when they have an injury and may feel uncomfortable with that fact. 

Yet, insects also most likely do not have emotions. 

Therefore, they are not going to lie in agony while dying, even if they feel some discomfort. 

Rather, they will move and maybe even thrash around when injured because they are trying to run away, as their instincts always tell them to do when they sense something’s not right. 

Conclusion 

Overall, a cockroach likely will not move when it is dead. 

If it does, it will only do so for a few seconds before becoming completely still. 

So, if you see a roach still moving, it is almost certainly alive.