For over one hundred years, millions of tourists have flocked to the ancient limestone Waitomo Caves on New Zealand's North Island, where stunning species of fungus gnat called Arachnocampa luminosa live. The genus is unique to New Zealand and Australia, and they are found in caves, grottoes, and other sheltered places. Arachnocampa means 'spider-worm,' as the gnat is known for the way their larvae hang strong vertical silk threads from the ceilings of their underground habitats. The threads are