How Nature Glows in the Dark

A group of jellyfish glowing in the deep, dark ocean.

Imagine living in the dark without a flashlight. It would be difficult getting around. But what if you could glow in the dark? There are many types of organisms that can glow on their own. Living things that produce light are called bioluminescent. Bioluminescence is a chemical reaction in a living thing. Most of these living things live in the ocean. The deep ocean is a dark place. Many bioluminescent organisms live in the ocean. They have changed so they are able to live in an environment without light. Many types of jellyfish are luminescent. They flash bright blue and green light to startle predators and defend themselves.

Fireflies lighting up a field at night.

Some bioluminescent organisms live on land. Fireflies, also known as lightning bugs, are luminescent. They produce light in special organs in their bodies. Fireflies glow in the night sky and send signals by flashing yellow and orange light. They use their luminescence to attract mates. Glowworms live on tree leaves in the forest. They also light up at night. Whether in the ocean or on land, bioluminescence is used to attract mates, warn predators to stay away, and even to hunt for food. Bioluminescence helps organisms survive.

What Can You Do? Complete an investigation to see what you can learn about fireflies in your own backyard. Sit quietly on a dark summer night and look for the flickering lights in the sky.

Photo Credit: (t)Emil Oprisa/Alamy Stock Photo, (b)Fer Gregory/Shutterstock