@Starltyz it isn't really about having a problem with lights, what happens in that unnatural light will reflect and interrupt the very distict flashing signals that male fireflies give off so that the females (who are stuck on the ground, lightless and flightless) won't be able to properly return the mating call. This is a big problem for firefly procreation, which is why the areas you see the most fireflies in are usually mostly untouched by humans as they are more successful in having children.