The firefly

📖 In short

On warm summer nights you might see little yellow or green lights flying over the grass, blinking on and off. They're fireflies! A firefly is a small soft-bodied beetle that makes its own light at the end of its belly.

🤩 Did you know?

There are about 1900 kinds of fireflies on every continent except Antarctica.
A firefly is between 5 and 30 millimeters long.
An adult firefly lives only 5 to 30 days.
In some countries thousands of fireflies flash all at the same time, like decorations!

🔎 Find out more

🌟 A lamp in its belly

Inside a firefly's belly, special substances react with air to make a cold light with no heat. The firefly can switch it on and off whenever it likes.

🔍 Light messages

Each kind of firefly has its own way of flashing, like a secret language. The male flashes as he flies, and the female answers from the grass with a special flash.

💡 The young glow too

Even firefly larvae glow; they live in damp soil and eat snails and little worms. Some people call them “glow-worms”.

🎯 They need darkness

Fireflies have become rarer in many places, because bright city lights stop them seeing each other's messages, and because people cut down the grass and trees they live in.