[Johnny555]

Chemical reactions by bacteria breaking down food produce light, enough for humans to see in only the darkest of places (if you live in a city, you won't ever encounter dark enough situations).

Some city folk have doors and window shades. My old apartment kitchen was on the windowless side of the apartment with a door. If you close the door (and unplug the microwave), it was pitch black. Though I never saw any glowing food, not even the spoiling fruit on the counter.

[jrockway]

I have the same kitchen setup. I develop film in there with the door closed. Nothing has ever looked fogged.

(I'm talking about developing sheet film in trays, btw... you don't need a darkroom to develop rolls or 4x5 sheets.)