Why do cockroaches turn upside down to die?

I lived in China for a year and these f**kers ruled my world. When I saw them on their backs, I cried with joy!

Good question. I have no clue, but it’s damn comical!

never really noticed that. great question

I went looking for an answer and I actually found something without expecting to. It appears to me that the following answers might be speculation only but I’m not sure.

(1) Roach has heart attack while crawling on the wall. OK, so maybe roaches don’t have heart attacks. Just suppose the roach croaks somehow and tumbles earthward. The aerodynamics of the roach corpse (smooth on the back, or wing side; irregular on the front, or leg side) are such that the critter will tend to land on its back. Or so goes the theory. Admittedly the study of bug airfoil characteristics is not as advanced as it might be.

(2) Roach desiccates, i.e., dries out, after the manner of Gloria Vanderbilt. This is what happens when you use Cecil’s Guaranteed Roach Assassination Technique, described elsewhere in this archive. The roach saunters carelessly through the lethal borax crystals, causing him to lose precious bodily fluids and eventually die. Since this process is gradual, it may happen that the roach simply conks out and dies on its belly.

(3) Roach dies after ingesting potent neurotoxins, e.g., Diet Coke, some traditional bug poison like pyrethrum, or the food served at USC cafeterias. Neurotoxins cause the roach to twitch itself to death, in the course of which it will frequently kick over on its back, there to flail helplessly until the end comes. No doubt this accounts for the supine position of the deceased cockroaches when observed.

Maybe it got stuck in that position
(like a turtle in the cartoons)
and ended up starving to death?

Okay. Probably not.

I’ve actually wondered this myself.
(Though not specifically cockroaches.) GQ.

It’s caused by rigor mortis, the stiffening of muscles following death. This causes the legs to be drawn under the body instead of being splayed out to the side, which makes the roach topple over.

Here’s a photo of a dead roach. You’ll see that it would be almost impossible to set it upright because of the position of the legs.

It happens with other bugs as well. Take a look at this dead spider.

That would totally explain cockroaches.
Though sometimes I also see flies on
their backs when they’re almost dead
—but before they’re actually dead.

Maybe they’re tired from standing
all of their lives and want to lie down
for a bit before they expire.

@Nimis Yeah, I think I’d attribute that to failed attempts to fly as they’re dying. The third part of @Bluefreedom ‘s answer has merit for the same reason: manufacturers of roach sprays formulate them so that the roaches will twitch and flail wildly as they die (sadly and I’m not making this up, this is to make the roach’s death more dramatic for our viewing pleasure). But because of the rigor mortis, even if the roach died a peaceful death, it would end up on its back afterwards.

That’s just terrible!
I wonder if there are
any quick death bug sprays?

I would totally buy it,
seeing as how I have issues
like that drowning bug guilt.

I think you can find a scientific answer in the website down below:

http://www.answerbag.com/q_view/105700