Night has fallen over the trees in Hendersonville, North Carolina, and South Bend, Indiana, where Common Eastern Fireflies are starting to blink. Across the world, people are stepping outside to watch these glowing insects. In Sozopol, Bulgaria, and Birkenweißbuch, Germany, European Glow-worms are shining in the grass. Whether you are checking the Alitaptap map or walking through your own backyard, seeing a firefly glow is a special moment. But our bright flashlights and smartphone screens can get in the way.
Fireflies depend on their lights to survive. Each blink is a signal. A male firefly flashes a specific pattern to catch the eye of a female waiting in the grass. When we shine a bright white flashlight or snap a photo with a phone flash, we flood the dark night with artificial light. This sudden glare ruins the insects' signaling. It also ruins our own night vision. If we want to enjoy fireflies without disturbing them, we have to learn how to watch them in the dark.
The Problem With White Light and Flashes
Think about walking out of a dark movie theater into bright sunlight. Your eyes hurt, and you have to squint. Fireflies experience something similar when a bright white light hits them. Their tiny eyes are built to spot faint yellow, green, or orange glows against a dark background. A white flashlight is blinding to them.
When a camera flash goes off near a firefly, the insect stops glowing. It might freeze or fly away. The flash washes out the subtle light signals that fireflies use to find each other. In places like Olympia, Washington, where California Glowworms live, and in places like Cowansville, Quebec, where Winter Fireflies are active, these insects need darkness to communicate. Bright lights interrupt their mating rituals. If they cannot find each other, fewer baby fireflies will hatch next season.
Phone screens are just as bad. Many people pull out their phones to take a picture or check the Alitaptap app while standing right next to the glowing grass. The bright screen shines right into the insects' habitat. It also ruins your own night vision. Once your eyes are exposed to a bright screen, the dark woods look pitch black again, and you will miss the faint blinks of fireflies around your feet.
Why Red Light Works Better
Scientists and wildlife watchers use red light instead of white light. Our eyes and the eyes of many insects do not react to red light the same way they react to white light. Red light has a longer wavelength. This means it has less energy, and it does not trigger the light-sensitive cells in our eyes that ruin our night vision.
If you need to walk along a path or check a notebook, cover your flashlight with a red filter or a piece of red cellophane. You will still be able to see where you are putting your feet, but you will not blind the fireflies or ruin your own ability to see in the dark. When you use red light, you can watch the fireflies without interrupting their night.
The Magic of Dark Adaptation
Your eyes have a superpower called dark adaptation. When you step outside into the dark, tiny chemicals build up in your eyes to help you see faint light. This process takes about twenty minutes. Once your eyes are fully adjusted, you can see shapes and movements in the dark that you missed at first.
When you keep your phone in your pocket and turn off all white lights, you let your eyes adapt to the night. Suddenly, the world looks different. You stop seeing just black shadows and start seeing the faint green glow of a European Glow-worm in Lithuania or the soft blink of an Abscondita anceyi in India. Dark adaptation lets you see the secret life of the night without bringing any artificial glare into the habitat.
How to Film in Near Darkness
Taking a picture of a firefly is tricky. Because their light is so dim, a normal camera phone cannot capture it without using a flash. And as we know, a flash ruins the moment. But you can still capture memories if you use the right settings.
Turn off your flash completely. If your phone or camera has a night mode or a manual setting, use a tripod or prop your hands steady on a fence post. Night mode lets the camera lens stay open a little longer to gather all the tiny bits of available light without blasting the scene with a white flash. Keep your screen brightness turned all the way down so you do not blind yourself or the insects.
Remember that you do not need to film everything. Sometimes the best way to experience nature is to put the camera away entirely. Stand quietly, let your eyes adjust, and just watch the flashes in the air.
Etiquette for Shared Viewing Spots
Firefly viewing spots are shared spaces. Whether you are visiting a public park in Seattle, Washington, or a quiet lane in New Brunswick, other people are trying to watch the insects too. Good etiquette makes the experience better for everyone.
Keep your voice down. Loud noises and bright lights both disturb wildlife and other observers. If you are using a red light to walk, point it down toward the ground instead of shining it up into the trees or across the field where other people are watching.
When you record your sightings for Alitaptap, do it respectfully. Step off to the side before you turn on your screen to pin your location on the map. Let other people enjoy the dark. By respecting the darkness, we protect the fireflies, keep our night vision sharp, and share the wonder of the night with everyone around us.