How and why fireflies glowing

Continuing the discussion from Bioluminescence: what’s about fireflies, firerunies and fireswimies?:

Different kind of fireflies may glow differently. Which I saw glowed protractedly, for a few minutes, how I think.

This glow does communication between individuals. They can glows in many ways, as flashes or synchronous like team of cheerleaders. It’s very interesting and exciting.
Therefore I want to see some amount of glowing creatures (big or small, fluffy or natatory).