If it seems like fireflies are disappearing, it’s because they are. Experts agree that their population decline has three root causes.

Many firefly species have specialized habitats and diets. And because they can’t fly far, they can’t just move to a new neighborhood once their environment changes.

Light pollution is another hazard. The ubiquitous skyglow in many areas is disorienting to fireflies. Bright lights can blind them or at least interfere with their light displays during mating.

As for pesticides, the biggest danger is to firefly larvae, which receive a double dose — through their watery environment and the small creatures they feed on.

Fireflies have existed for over 100 million years, so it would be a shame to see their lights go out. Firefly Watch, a nonprofit organization, suggests ways you can help them.