Amazing Places

Glowworms Give the Waitomo Caves a Brilliant Blue Nighttime Glow

You're about to gain a whole new appreciation for worms. One species of these squirmy, squishy, fleshy things turns the Waitomo Caves of New Zealand into literal living, breathing art. Who knew larva could be so beautiful?

It's Lit

The glowworm cave has long been known to the local Maori people. But in 1887, Maori Chief Tane Tinorau took English surveyor Fred Mace on an adventure to the caves of Waitomo to show him, and subsequently the world, its magnificence. They took a little raft down a stream into the caverns, and looked up to see glittering blue stars somehow illuminating the cave. Mace prepared an account of the expedition, made a map, and supplied photographs to the government. Soon, too, Tane Tinorau was operating cave tours for more than just other Maori.

The Worms at Night Are Big and Bright

It's not magic; it's just worms. Caves are cool enough geologic formations on their own, but the secret sauce that makes the Waitomo caves super awesome is its living inhabitants. The ceiling of the cave is covered in thousands of bioluminescent little creatures: the new Zealand fungus gnat arachnocampa luminosa, which is a type of glowworm.

Just as the caves wouldn't be anything remarkable in the daylight, these insects aren't very interesting in their mosquito-sized adult stage. But as larva, the little gnats turn the underground scene into a walk-in Lite-Brite. The babies have transparent skin through which a greenish blue light can shine, thanks to a chemical reaction that occurs in an organ in their butts. The purpose of the glow is to attract food and mates. And, of course, tourists.

A Time-lapse of New Zealand's Glowworm Caves in 4K

What Makes The Waitomo Caves Glow?

The science behind bioluminescence.

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Key Facts In This Video

  1. The Waitomo Caves display glowing blue bioluminescent glowworms. 00:23

  2. The New Zealand fungus gnat glows a brilliant blue in its larva stage. 00:53

  3. The New Zealand fungus gnat suspends a fishing line of silk covered in mucus to catch prey. 01:48

Written By Joanie Faletto July 2, 2015