GLOW WORM (Puratoke)
Found in caves, deep ravines and damp banks.
In Arthur's Pass you can view them at night, by wandering a short way into the dark beech forest, they inhabit the undersides of small clefts in the forest floor.
The Glow Worm is the larva of a small gnat which suspends itself from the roof of caves etc. by a thin silken threads.
The light comes internally from the larva and is projected through the transparent skin to the threads for the purpose of attracting and capturing minute insects.
The larva feeds by pulling in the threads to which a flying insect is snared.
The gnat emerges from the larva after about two months. It is nocturnal, also luminous, and has a flying life of only one or two days.
The two best known larvae sites are to be found at waitomo caves in the central North Island (near Te Kuiti) and Te Anau in the South Island.