system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why do flies constantly choose to fly near and bother humans?
gpt
They don't. Flies don't consciously choose to do anything, as far as we know. They're running on pure hard-wired instinct.

Flies are attracted to any strong meat-ish smell. And you, being mostly meat, smell meat-ish. They're hoping they'll find some dead flesh to lay their eggs in. You're not dead, so you're not a good option for this, but flies are far too stupid to know that and will keep circling your meat smell until something better comes along.