The glow worm (Arachnocampa luminosa), is unique to New Zealand. Thousands of these tiny creatures radiate their incredible blue luminescent light throughout the caves.
The cave glow worm is no worm at all. It’s a fungus gnat larva — predatory, and, if the going gets rough, cannabalistic. The handful of species are found only in New Zealand and in eastern Australia. A newly hatched larva measures just a few millimeters long, but it soon sets about spinning a series of sticky fishing lines it suspends from the cave ceiling.