ON LAND
In a forest in North America, mushrooms glow with an eerie green light. Fireflies signal one another in a pattern of yellow flashes.
Deep inside a cave in New Zealand, a hungry glowworm can produce over 40 sticky lures!
IN THE OCEAN
In the deep seawater world of complete darkness, the only light comes from living things:
Firefly, © Jeff. J. Daly/Alamy; Waitomo glow worm larvae, © Kjell B. Sandved/Visuals Unlimited; deep-sea anglerfish, courtesy of Edith Widder/HBOI.