system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does bug spray affect an insect?
gpt
Bug spray is usually nerve gas for bugs.  
Depending on the exact compound it causes the nerves to fire constantly, randomly or not at all. In any case it's not firing when it's supposed to or firing when it's not supposed to. The bug then suffers something like a heart attack or stroke.