On a clear August night, step outside and look up. If you live far from city lights, you might see hundreds of white stars. You might even see the glowing band of the Milky Way galaxy stretching across space. Now look down at the grass near your feet. On that same quiet night, you might spot soft yellow dots blinking in the dark.
Those blinking dots are fireflies. Just like stars in space, fireflies rely on real darkness to shine. When streetlights, porch bulbs, and bright store signs flood the night, the stars seem to disappear. The fireflies do too. But the bugs do not fly away to another planet. They are still sitting in the grass. We just cannot see them, and more importantly, they cannot see each other.
Today is August 5, 2026. Over the last three days, observers on Alitaptap have logged dozens of sightings across the world. Someone in Ann Arbor, Michigan, spotted a Common Eastern Firefly near Maple and Haisley. Another member saw one along N Goldendale Drive in Brown Deer, Wisconsin. Halfway across the globe, an observer recorded a Rimmed Window Firefly in Kwun Tong, Hong Kong. In Avremesnil, France, someone logged a European Glow-worm resting in the dark.
All of these bugs have something in common. They need the night sky to stay dark so their tiny lights can do their job. People who work to protect stars and people who work to save fireflies are actually fighting for the exact same thing.
How Light Drowns Out a Tiny Flash
Fireflies do not make light just to look pretty. Their glow is a secret code. Male fireflies fly above the grass and flash a special pattern. Female fireflies sit on low leaves or stems and watch. When a female sees a male of her own species, she flashes back.
Think of this conversation like two people talking across a dark room with flashlights. If the room is pitch black, even a tiny toy flashlight is easy to spot. You can send code back and forth without any trouble.
Now imagine someone turns on a massive spotlight in the middle of that room. Suddenly, your tiny flashlight beam is invisible. You can click the switch all night long, but the person on the other side of the room will never see your message.
That spotlight is what light pollution does to a backyard. Scientists call artificial night light light pollution because it ruins the natural darkness that night animals need. When a porch light floods a garden, male fireflies keep flying and flashing. But the females sitting in the shadows cannot see them well. Worse yet, the males cannot spot the faint answer from the females.
If fireflies cannot see each other's flashes, they cannot mate. When they cannot mate, no new firefly eggs are laid in the soil. Over a few years, a yard that used to be full of summer flashes can go completely dark.
The Link Between Stars and Fireflies
Astronomers are scientists who study stars, planets, and deep space. For more than fifty years, astronomers have warned us about losing the night sky. When light from cities shines up into the air, it bounces off dust and water drops in the atmosphere. This creates a bright background glow called skyglow.
Skyglow acts like a pale curtain pulled across space. It hides faint stars, distant planets, and the center of our galaxy. It also makes the ground brighter at night than it should be.
Firefly scientists, called entomologists, noticed the exact same problem on the ground. A dark field lets a firefly light carry across dozens of feet. A field washed in skyglow flattens that contrast. Contrast is the difference between bright and dark. Without high contrast, a firefly flash loses its power.
This means that dark sky parks and starry night reserves are not just good for telescopes. They are giant safe zones for glowing insects. When a town agrees to lower its outdoor lighting to help people see the stars, the fireflies in the grass get an instant boost.
What Is a Lumen?
When you go to a hardware store with your family to pick out a light bulb, you will see the word lumen printed on the box. What is a lumen?
A lumen is a unit that measures how much light a bulb puts out in total. You can think of lumens like the volume knob on a radio. A low lumen number is like a quiet whisper. A high lumen number is like a blast of loud music.
An old-fashioned flashlight might put out 50 lumens. A small nightlight in your hallway might put out only 10 lumens. But a big floodlight on the side of a garage can blast out 1,500 lumens or more.
Here is how lumens look to a firefly:
- 10 to 100 lumens: Very soft light. Good for seeing a walkway step without disturbing night animals.
- 400 to 800 lumens: Bright enough to light up an entire driveway. This level of light can easily drown out firefly signals nearby.
- 1,500 lumens and above: Extremely bright. This creates heavy glare and washes out the dark for a long distance around the fixture.
To help fireflies, we do not need to live in total pitch darkness all the time. Humans need light to see steps, locks, and driveways so we stay safe. The secret is using only as many lumens as we actually need. Choosing a bulb with 200 or 300 lumens instead of 1,200 lumens keeps the path safe for humans while keeping the night dark enough for bugs.
What Is a Shielded Fixture?
Lumens measure how bright a light is. But where that light goes is just as important. That is where fixture design comes in.
Imagine holding a bare light bulb in your hand outdoors. The light shines in every single direction at once. It goes up into the clouds. It goes sideways into your neighbor's window. It goes sideways into the trees where fireflies are resting. Only a tiny fraction of that light actually hits the ground where you are walking.
Light that goes up into the sky is wasted energy. Light that goes sideways into eyes is called glare. Glare makes it harder for human eyes to adjust to the dark, and it blinds nocturnal insects.
A fully shielded fixture solves this problem. A shielded fixture has a solid cover on the top and sides. Usually, it is made of metal or dark glass. The bottom is open.
When you turn on a shielded light, all the light is pushed straight down toward the ground. None of it spills up into the sky to hide the stars. None of it shines sideways into the bushes to hide female fireflies.
Think of a shielded fixture like a person wearing a baseball cap. The brim of the cap blocks the sun from shining into your eyes and keeps your shadow focused where you look. A shield on a light bulb does the same thing for the night.
By using a fully shielded fixture with a low-lumen bulb, you get light exactly where your feet need it. The sky above stays dark for astronomers. The bushes nearby stay dark for fireflies.
Choosing the Right Color of Light
Brightness and direction are two pieces of the puzzle. Color is the third piece.
Not all light looks the same. Have you ever noticed that some LED bulbs look bright blue-white like a hospital room, while others look soft and yellow like a campfire?
Scientists measure light color using a scale called Kelvin. You do not need to remember the math, but here is what you need to know about colors at night:
- Blue-white light (high Kelvin, around 4,000K to 5,000K): This light looks like daytime sun. It tricks human brains into thinking it is morning. It also tricks insects. Blue light spreads farther in the air and causes more skyglow.
- Warm amber or yellow light (low Kelvin, under 2,200K or 3,000K): This light looks warm and soft. It spreads less through the air.
Fireflies are especially sensitive to blue and green light. Many species communicate using yellow or green flashes. When bright blue-white outdoor lights fill a yard, they flood the exact colors fireflies use to send messages.
Switching outdoor bulbs to warm yellow or amber LEDs helps keep the natural dark intact. It feels cozy for people, and it leaves the night spectrum open for insect signals.
Real Sightings from the Alitaptap Map
Data from Alitaptap shows how fireflies react to different environments. Look at the sightings recorded by citizen scientists over the first few days of August 2026.
In Chicago, Illinois, a volunteer logged a Common Eastern Firefly in Lincoln Park. In New York City, observers logged sightings along Lafayette Avenue and Woodhaven Boulevard. Fireflies can survive in cities, but they are often restricted to dark pockets like big parks or quiet, tree-lined yards away from streetlamps.
In contrast, look at observations from places with darker surroundings. In Broomfield, Colorado, a user spotted a Dark Firefly. In Gaspé, Quebec, someone logged a Black Firefly near Forillon. In Olathe, Kansas, and Louisville, Kentucky, members spotted Sneaky Elves. In rural France, near Manigod and Saint-Brice-sous-Rânes, European Glow-worms were logged in grassy fields.
When we overlay firefly map data with light pollution maps, a clear pattern emerges. In areas where night lights are unshielded and bright, firefly counts drop. In places where neighbors turn off unnecessary lights or use shielded fixtures, fireflies thrive.
Small Changes That Make a Big Difference
You do not need to turn off every light in your city to make a difference for fireflies. Conservation starts right at your own front door.
Here are four easy steps you can talk about with your family:
- Turn off lights you are not using. If nobody is on the patio, flip the switch off.
- Motion sensors are your friend. A light that turns on only when someone walks up the path stays off most of the night. This saves electricity and keeps the yard dark for wildlife.
- Shield your outdoor fixtures. Make sure outdoor bulbs are capped so light points down, not out or up.
- Keep it warm and dim. Use lower-lumen bulbs with a warm amber color instead of harsh white lights.
When you protect the night sky, you are doing double duty. You are helping astronomers look deep into the universe to discover distant stars and planets. And right down on Earth, you are giving fireflies the dark stage they need to perform their summer light show.
Next time you see a firefly blink in your garden, look up at the stars above it. Both lights belong to the night. By keeping our lights smart and dim, we can make sure both keep shining for years to come.