Arachnocampa luminosa - glowworms of New Zealand.
If you turned your light off while inside a cave in most parts of the world, you'd be lucky to see anything but inky darkness. In many New Zealand caves, however, you may just be able to make out the shadowy forms of nearby stalactites in a dim, blue glow. Wait a few minutes for your eyes to adjust and you'd nearly be able to read a book by the light of hundreds of tiny glowing gnats in their larval stage. Every year tens of thousands of tourists venture underground to experience glowworms in what has become a key part of New Zealand's tourism industry.
Neil's photos featured in a New Zealand Geographic story on the glowworm tourism industry.