Why do glow worms glow?

Written by: Cameron Ward

Published: February 28, 2019

Reading time: 3 mins

Most people may squirm at the thought of the creepy crawlies of Australia, but one small worm has climbed up the charts in the country’s popular animals, all due to its ability to glow in the dark.

Imagine you are deep within the Springbrook National Park, trekking through the lush greenery as the sun sets behind you. You arrive at the arched caves, stepping into their shadowy entrance until you are completely immersed in darkness. Except you realise, you have not been swallowed up by the dark, as there is light littering the ceilings of the caves, almost like stars in the sky. These blue lights illuminate the rocky walls, creating an enchanting spectacle for all to see.

These are in fact, not man-made lights, but completely natural lights made by the famous Glow Worms. Thousands of tourists visit these caves yearly, watching in fascination at this enchanting display of nature. But how do these small creatures create this mesmerizing glow?

About the Glow Worms

Despite the name, glow worms are in fact not worms at all, but instead are the larvae of a primitive fly, the fungus gnat. The larvae, which is a similar size to a caterpillar, spend nine months within these caves, feeding and transforming until they eventually become a full fly adult, resembling a large mosquito in appearance. The larvae stage is actually a lot longer than their adult period, which only lasts a couple of days before they perish.

The Science

Its natural blue/green light that has made these worms famous is all due to a chemical reaction. It occurs all inside the creature’s bodies, with a waste product, an enzyme, an energy molecule, and oxygen all reacting together to create this natural glow.

The Reason Why

These glow worms don’t light up just for our amusement, but instead, have a completely justifiable reason why they produce the glow. Basically, it is all for food! They use the light as a way to draw in prey, similar to a bug light zapper. The bugs become spellbound, slowly drifting closer and closer until they are caught in the worm’s web. These webs differ from a spider, instead of being a long silk thread that hangs from the ceiling of the cave, comparable to a long dangling drool. The sticky residue on the silk thread traps the insects, leaving them hanging there as the worm drags up the thread to devour their prey.

How to see them

If you are travelling around the tropic lands of Australia, you can easily see these creatures within their natural habitat. Nestled deep within one of the World Heritage Listed National Parks; named the Springbrook Park. A simple drive from the Gold Coast can have you instantly within the lush greenery of the rainforest, with ancient trees and unique wildlife to marvel at. Immerse yourself in nature, walking deep within the forest until you reach the arched caves of the national park. These dark and dreary caves come to life after sunset, with the ceilings sprinkled with blue lights, similar to stars in the sky. There are tours offered to visitors every day, where visitors trek through the lush greenery before seeing the creatures, giving them a wonderous and unforgettable journey into the spectacular Aussie rainforest.

Related article: Things to do on the Gold Coast when it’s raining

Cameron Ward
Cameron Ward
Managing Director at Sightseeing Tours Australia

Cameron Ward turned his travel passion into a thriving Australian tourism business. Before he co-founded his own business, Sightseeing Tours Australia, he was enjoying being a Melbourne tour guide. Even now, Cameron delights in helping visitors from all around the world get the most out of their incredible Australian trip. You’ll see Cameron leading tours or writing about his favourite Australian places where he shares his local insights.