A cave insect fishes for prey with glowing silk fishing lines

Arachnocampa luminosa, the New Zealand glowworm, is a fungus gnat larva that lights its rear end blue-green to lure flying insects toward the cave ceiling. It then dangles up to 70 sticky, mucus-beaded silk threads below itself and reels in whatever gets stuck. The light comes from a bioluminescent organ built from modified excretory tubules.

— Wikipedia contributors, Arachnocampa luminosa — Wikipedia article