New Zealand Glow-Worm

Arachnocampa luminosa is endemic to New Zealand and is technically not a worm — it's the larval stage of a fungus gnat. Larvae live on cave ceilings (and damp forest banks) where they spin a horizontal silk gallery, then hang dozens of vertical 'fishing lines' — silk threads up to 50 cm long, each studded with sticky mucus beads. The larva produces a continuous blue-green bioluminescence from its abdomen that attracts flying insects toward the trap. When prey gets stuck in the lines, the larva hauls them up and consumes them. The bioluminescence is one of the most efficient natural cold-light reactions known, comparable to fireflies but biochemically distinct — different luciferin, different luciferase. The species is best known from Waitomo Cave on the North Island, where commercial visits attract hundreds of thousands of tourists annually. Adult glow-worms (the gnats) live only a few days, do not eat, and exist only to mate. The larval phase, by contrast, lasts 6–12 months — the entire 'glow-worm' you see is a long childhood.