Mochi Isle
Bioluminescence · Crystal MineScience for kidsWhy do some living things glow?
In short: Some living things use a chemical reaction inside their bodies to make light. This is called bioluminescence. They use it to lure prey, signal to each other or startle enemies. Not all cave creatures glow, though.
How it works
Glowing creatures contain a substance called luciferin. With help from a special enzyme (a natural helper that speeds up reactions), it reacts with oxygen and gives off light. Very little heat is made, so it is often called 'cold light'. A glow stick works in a similar way: a chemical reaction, not electricity.
The light has many jobs. Fireflies flash to find a mate. Deep-sea anglerfish dangle a glowing lure to tempt smaller fish closer. Some squid and shrimp squirt out glowing liquid when attacked, then slip away while the predator is distracted.
Bioluminescence is most common in the sea, where many deep-sea animals glow. On land it is much rarer: fireflies, a few mushrooms and some small insects. Most cave animals do not glow at all; they rely on touch and smell instead.
Where to see it in New Zealand
New Zealand's glow-worm is found only in New Zealand. It is the larva of a fungus gnat that shines blue-green at Waitomo Caves, the Te Anau Glowworm Caves and along many damp bush tracks, catching small insects drawn to its light with sticky threads.
Try it together
Hold a glow-in-the-dark sticker under a lamp for a few minutes, then take it into a dark room and watch it fade. The sticker must soak up light first; glowing creatures make their own. With an adult, try a night walk to spot glow-worms, keeping torches pointed away.
Kids also ask
Is the light from glowing animals hot?
No. Almost all the energy becomes light, with very little heat, which is why it is called cold light. Old-style light bulbs were the opposite, turning most of their energy into heat.
Are glow-worms really worms?
No. Despite the name, New Zealand glow-worms are insects: the larvae of a small fly called a fungus gnat. Once they turn into winged adults, they live for only a few days.
In the game, “Bioluminescence” is a nature card on Crystal Mine.
Your child finds this card by reaching the right place or meeting the right weather on the island, and lights it up by answering the question on the back. Tap the button below and the game shows your child which island it is on and how to find it. Mochi Isle is a browser learning game for ages 5 to 18; the main island and the daily lesson are free.
Find “Bioluminescence” on the island ↗ All cards from Crystal Mine