Luminescent glowworms (aka Arachnocampa luminosa) fill the Waitomo Glowworm Caves in New Zealand, mesmerizing visitors with their radiant bodies. The organic, larva-like creatures illuminate the otherwise pitch-black cavernous space as a chemical reaction, similar to bioluminescent microorganisms in Australia and reactive jellyfish in the British Columbian coast.
Interestingly, these glowworms are exclusively found in New Zealand and choose to reside in caves as they approach their larval stage, which can last anywhere from 6 to 12 months long. In the natural, rocky vault they are able to spin silk nests and hang long strings holding beads of mucus from the ceiling without added complications of their strands getting tangled due to wind. After all, this is their means of survival, serving as a trap for prey.
Though the caves are especially beautiful when the glowworms are at their brightest on the ceilings, like a sea of shimmering stars, it also means that they are at their hungriest. The larvas glow to attract their next meal into the threads they've hung below them, though visitors need not fear as they pose a greater threat to the glowworms who react to human interference by retreating back into their nests.
Waitomo Glowworm Caves website
via [thinx, Spellbound, Just The Travel]