The New Zealand glow-worm is the larvae of a type of gnat that lives in dark damp places such as caves. To attract food, the larvae can use their tails to produce light. Sometimes the larvae sit in a kind of web and lower sticky threads down into the water these attract midges who get stuck to the threads then they pull them up and eat them for tea.

The best place to see these glow-worms is in Waitomo cave in the North Island of New Zealand. A river flows into the caves following a passage full of stalagmites and stalactites. As you arrive in the main cave the light produced by the glow-worms is so bright you can read the time on your watch in the cave.