This article originally appeared on AccuWeather.com.
Summertime as a kid in the eastern half of the United States usually means no school, long hours playing outside and nights that often end by catching fireflies in carefully closed palms.
It's a special summer tradition for many, but a diminishing firefly population could mean future generations won't capture those same memories.
Nostalgic adults have noticed an absence of tiny flashing lights in their backyards during recent summers in the Northeast.
In 2010, researchers presented evidence of the decline of numerous firefly species in 13 countries at the International Firefly Symposium. Since then, conferences, research papers and citizen-science projects have continued to draw attention to the issue.
Both Ben Pfeiffer, founder of Firefly.org and Marc Branham, a professor of entomology and nematology at the University of Florida, agree that despite the lack of research, human activity has a major impact on dwindling populations.
Urban sprawl is one of the greatest threats to the insects. Lights from homes, cars, stores and streetlights disrupt flash patterns, leading to lower rates of reproduction.
"Fireflies use their lights to create flash patterns that help them find potential mates and communicate," Branham said. "Because fireflies gauge the time of day based on the darkness, light pollution is causing them to miss their [reproduction] activity window."
Along with light pollution, the use of pesticides and unnatural fertilizers can permanently destroy a firefly's habitat.
Because fireflies seek shelter in grassy areas, the paving of forests and open fields destroys potential habitats. An uptick of activity in waterways also proves disruptive, according to Firefly.org.
However, more work needs to be done to fully comprehend the damage human activity has done to their population.
"The lack of researchers studying fireflies makes it difficult to collect data on them," Pfeiffer told AccuWeather. "Their short flight period and short lifespan can [also] make it difficult to track them."
A firefly's time on Earth lasts an average of two months, though their presence seems to transcend time.
These bioluminescent creatures create the most efficient light in the world. One hundred percent of the energy they emit is light, as opposed to an incandescent light bulb, which emits 10 percent of its energy as light and the rest as heat.
According to Pfeiffer's website, a firefly's light is referred to as a "cold light" because it does not produce heat.
Firefly Watch, a citizen-science project, allows people to track fireflies from their own backyard and submit their data to researchers at the Museum of Science in Boston.
The data should help researchers gather more insights into the population decline.
"There's not a lot of evidence to prove or disprove their disappearance, but what is understood is the urgent need to conserve firefly habitats," Pfeiffer said.
However, experts believe that humans can help alleviate the growing concern.
As for those summer nights spent catching lightning bugs? According to Firefly.org, it's all in good fun, as long as you catch carefully.
Once caught safely in a net, place fireflies in a jar with holes in the lid. Put a moist paper towel inside the jar to create humid air.
Don't keep them confined for more than a day, and try to release them at night, when they are most active and can avoid predators.