Gone in a Flash?

During twilight, there’s a sudden spark of light, followed by another. All at once, a field becomes filled with twinkling firefly flashes.

Fireflies are found on every continent except Antarctica, and there are nearly 2,000 species. But all over the world, people are seeing fewer fireflies than they used to. Firefly numbers are falling.

It’s twilight. There is a sudden spark of light. Then another. Then a field fills with twinkling firefly flashes all at once.

Fireflies are found on every continent except Antarctica. There are nearly 2,000 species. But people are seeing fewer fireflies than they used to all over the world. Firefly numbers are falling.

“Populations are decreasing around the world,” says Jonathan Copeland. He’s a biologist from Georgia Southern University who studies fireflies. “The causes are unclear.”

Researchers suspect one culprit might be light pollution. Many firefly species produce light to attract mates. Males fly around at night, flashing their message to females in the grass below. When a female sees a male she likes, she blinks back. But with so much light given off by homes and cities 24 hours a day, it can be hard for fireflies to see each other’s flashes.

Populations are decreasing around the world, says Jonathan Copeland. He is a biologist from Georgia Southern University who studies fireflies. The causes are unclear.

Researchers suspect one culprit might be light pollution. Many firefly species produce light to attract mates. Males fly around at night. They flash their message to females in the grass below. A female blinks back when she sees a male she likes. But it can be hard for fireflies to see each other’s flashes. This is because of the light given off by homes and cities 24 hours a day.

Steven Puetzer/Getty Images

Fireflies produce light in their abdomens.

Another reason firefly populations may be shrinking is habitat loss. Fireflies prefer areas where there’s a lot of moisture —like forests, meadows, and mangrove swamps. But many of these places are being cleared to make way for houses, highways, and other developments.

Some countries are taking action to help fireflies. Malaysia, Thailand, Japan, Taiwan, and China have set up sanctuaries to protect firefly habitats. In these firefly reserves, people can see the dazzling insects up close. Money earned from admission fees goes toward conserving the fireflies.

These efforts will hopefully ensure that fireflies keep twinkling for many more years to come.

Another reason firefly populations may be shrinking is habitat loss. Fireflies prefer areas where there is a lot of moisture. They like forests, meadows, and mangrove swamps. But many of these places are being cleared. They are being replaced with houses and highways.

Some countries are taking action to help fireflies. Malaysia, Thailand, Japan, Taiwan, and China have set up sanctuaries. They want to protect firefly habitats. People can see the dazzling insects up close in these firefly reserves. Money earned from admission fees goes toward conserving the fireflies.

These efforts will hopefully ensure that fireflies keep twinkling for many more years to come.

Photinus marginellus is a firefly species found in North America. On a separate sheet of paper, continue its flash pattern for 6 more seconds so there is a total of 12 seconds.