system
Given the following post, respond as if you're commenting on Reddit:
human
Why are dead roaches always upside down?

Whenever I'm unlucky enough to stumble upon one they're always in that position.
gpt
Not all of them do. If you're killing them with some sort of pesticide or neurotoxin, like Raid, their dying brains will cause spasms in their muscles. Frequently this will flip the roach over onto its back where it will then spasm uncontrollably and helplessly until brain death is reached. Most of the dead roaches you see are probably poisoned, which would explain why you're finding them that way. Roaches rarely meet their maker in a natural way out in the open; if they were to die naturally, they would probably be already too weak to leave the burrow. Too weak and slowly dying, the roaches dying of old age will most likely be on their bellies. But you'd never see them.

To recap: roaches have mini seizures when they're poisoned, flipping them onto their backs. By sampling bias, you probably only see the poisoned ones, and draw the conclusion that dead roaches die on their backs.