Counting Fireflies
Are fireflies vanishing or making a comeback? Our family investigates . . .
I did not grow up with fireflies, except for ones in books. My childhood reading included a hearty supply of stories where fireflies lit up the nights. Lucky kids on the East Coast and in the South chased them with nets, collected them in jars. Fireflies were woven into setting descriptions and sprinkled into cover art, evoking summer magic. I didn’t care what the story was about. If it had fireflies, I was in.
We had no fireflies in suburban Seattle. Nor did we have them in Cle Elum, Washington, where I attended summer camp. I’d squint fiercely into the darkness until my eyes throbbed, sometimes mistaking campfire sparks for lightning bugs. A camp counselor finally took pity and told me the west coast has no fireflies. No fireflies at all! Once I learned that, my summers seemed dimmer, less enchanted, compared to those glowing summers in books.
Recently, I learned the counselor was incorrect. Fireflies live throughout the United States, and on all continents except Antarctica. But I would have had to look extremely hard to spot them in Cle Elum. Most adult males of the species in western states do not produce any light. The females flash weakly, and only while they’re on the ground. Some western species are more active by day, communicating by pheromones instead of bioluminescence.
The fireflies from my summer reading would have been an eastern species, likely the common Photinus pyralis. These males light up as they fly around looking for females. The females flash back if they like the pattern they see.
When I moved to Massachusetts for college, and stayed one summer for a campus job, I scanned nearby fields night after night. No fireflies appeared. When I eventually settled in Massachusetts, I lived in Boston, and then in a densely populated town, where moths, not fireflies, gathered under streetlights. I eventually forgot about my quest until after my son was born, when fireflies magically reappeared in the books we read together.
A number of G’s earliest picture books featured fireflies. One board book had us counting them. Over and over, we’d count up to ten fireflies, tracing their flight patterns with our fingers. Another book was best read in darkness; the fireflies glowed. One favorite was from my own childhood, Sam and the Firefly, featuring an artistic lightning bug and his owl friend, Gus.
Did G think it strange to count or read of a creature he’d never seen? Apparently not. Maybe for him they were as fantastical as a sloth, or a dragon, both of which also appeared in his books.
G aged out of picture books, then out of middle grade novels. Fireflies slipped from my mind once again.
I never imagined I’d be middle aged when I finally saw them.
We’d been living in a semi-rural town outside of Boston for several years, but I’d never searched for fireflies. I’d pretty much given up.
One evening in late June, I went outside to pick dog toys off the grass. Suddenly, I saw sparks. Flickers hovering above the grass. One here, one there. Darting, dipping. Zigging, zagging. Fireflies! Just like the books had described them! I laughed in delight.
What accounted for their appearance now? My online sleuthing that evening turned up conflicting facts. There are over two thousand species of fireflies globally, some of which are decreasing. Yet they also seem to be coming back. So are they declining or rebounding?
Many studies show the scale tips toward decline, thanks to light pollution, habitat fragmentation, and insecticide use. Light pollution, emanating from streetlamps and landscape lighting, disturbs their mating rituals. When the flashing beetles cannot see one another’s glowing abdomens, they can’t respond in turn. Matches are not made.
Shrinking habitats also impact life cycle activities. Weeds are whacked or poisoned. Insecticides can stunt larval development because they penetrate soil, where the larvae spend 95% of their lives. In fact, the larvae may live underground one to two years before pupating to become adults—if they’re lucky to make it that far. Researchers have found even residual concentrations of insecticides in the soil may continue to expose larvae to toxins. Considering the larvae can serve as natural pest control, eating snails and slugs, it seems we should be welcoming them. But not everyone knows this.
Dangers above ground threaten fireflies too. Lawns mowed too frequently harm adult beetles who linger there. All this time I’d been looking straight ahead to find glowing insects in flight. Yet the secrets to their presence, or their absence, might have been found beneath my feet all along. Soil health is critical to their survival.
In contrast, some recent anecdotal reports point to hopeful trends. Fireflies have been increasingly noticed in parts of the United States.
Was I witnessing a firefly comeback in my yard? An image flashed into my mind: a tired, aging, glam pop band dusting itself and going on tour, one last hurrah before the stage darkened. Maybe this appearance in my yard was temporary. I shouldn’t get too excited.
But I was excited to discover that scientists are driven by similar questions. They want to know where firefly populations are growing or shrinking, which species are most at risk, and what environmental issues impact them. According to a 2021 study, at least eighteen species of fireflies in North America, or fourteen percent, are critically endangered, endangered, or vulnerable. Unfortunately, data gaps make it hard to know how many firefly species meet the criteria for being at risk of extinction.
Deep breaths. Extinction! A frightening word. Permanent. Could we do anything to help?
Yes. Enter Project Firefly Watch!
Fortuitously, Tufts University’s call for community scientists came onto my radar the next day, in a Massachusetts Audubon Society newsletter. I could observe fireflies and record data for researchers. All I needed was a “habitat,” my yard or a field, and ten minutes at least once a week between June and July. Anyone in North America could participate. No fireflies? No problem! All firefly data, even non-sightings, is helpful, the website assured.
I quickly set up an account. My pulse quickened. Firefly Watch was just what I needed to lift my mood.
I’d spent the previous weeks clicking on dire news flash headlines. Floods and fires. The January 6 hearings. Atrocities in Ukraine. Mass shootings. Roe overturned. One grim news flash after another. Threats came from all directions. My moods had two settings. Fury. Despair.
I had no attention span for anything other than horrible stories. I checked out of conversations mid-way. My words trailed off, and soon after, my thoughts.
In the past, my husband and I might rehash current events. Now Jim and I skirted around these topics. Perhaps we were equally exhausted. Perhaps we didn’t want so much toxic news to infect our son. At fifteen, with his antennae up, he seemed especially vulnerable to hearing about the bleak future facing Generation Z.
At least now there were fireflies to distract me. All I needed was ten minutes to sit, with cycles of three ten-second viewings. I could focus that long.
I ran outside. The garage light illuminated a broad patch of lawn. I switched it off with a pang of guilt. A few minutes later, tiny glowing lights appeared, inches up from the grass.
I set my timer and observed. I squinted in the darkness as intently as when I was a summer camper. I tallied my numbers on a notepad. G’s firefly counting books had trained me well!
Back inside, I logged on to the Firefly Watch web portal. The information fields swam before my eyes. Had I really seen ten fireflies? Or ten flashes from the same fly? Two flies, five flashes each? Counting something nearly invisible, in darkness, was harder than I thought. I read over the guidelines again. More doubt set in. Had I seen single flashes close together, or a series of double flashes? Was the flash pattern a “J” shape, or one beetle responding to another beneath it? I watched the training video, then repeated my observation outside. I still doubted my perceptions. If I was one of the community scientists that was going to monitor and save fireflies, these insects were probably doomed.
I logged what data I could, confident only in the weather conditions (high 70’s, scattered clouds) and light sources (distant driveway lantern, moon). Hopefully I’d get better with each observation. Maybe in time I’d even grasp the language of lightning bugs.
Fireflies aren’t just flashing randomly. They are sending deliberate messages to attract mates, to distinguish different firefly species, and to deter predators. The chemical reaction that takes place in their abdomen and produces light makes them taste terrible. Some flashes function as warnings. Some larvae even glow underground to tell predators to back off.
I wanted to witness these meaningful exchanges. The adult males, I read online, displayed longer, more elaborate flash patterns while in flight. The females would respond from the bushes and grass. I’d need to look high and low to detect their dialogues, to see their stories.
An unexpected rainstorm changed my plans on Day Three. I dozed over a novel while waiting it out. At one point, I heard a muffled voice downstairs. My husband? No, the TV. News. I let the rain wash the voice away and fell asleep over my book.
When Jim came up to bed, he said he’d fallen asleep on the couch but awakened to the most incredible sight. “Fireflies!” he said. “Swarming right outside the window!”
“What? Why didn’t you tell me?” I spluttered.
“I did,” said Jim. “I called out for you. I guess you didn’t hear.”
I ran outside. The show was over. Annoyed that I’d missed the message, and the show, I crawled into bed. I turned off the light.
Reporting for Firefly Watch every night, I gradually noticed not just the number of flashes, but their length and the time in between. I also determined that I was seeing fewer insects than I’d first thought. What looked like two fireflies was likely a single bug with a double flash. Yet some nights I noticed more single flashes than double. Sometimes flashes came fast. Others, slow. I compared flash signals to a cheat sheet I found online. After two weeks of intense focus, I could identify the looping letter J pattern of Photinus pyralis. But the other eight species dialects eluded me. Either I didn’t have those species in my yard, or I couldn’t understand them.
I experimented with time, starting my observations at dusk, then later. I switched my habitat from the front yard to the back. The flash signals were easier there, against the woods behind our house.
Were fireflies more active after rain? Did I have multiple species? Did they come out at different times? I didn’t always have answers, though I had investigative partners all over North America. This community science project had launched in 2008; thousands of people had contributed to firefly data since then. Other observers were out there, staring into the night, tracking tiny sparks. I felt part of something bigger. Still, we didn’t have a structured way to communicate. I also wanted more eyes on the ground in my designated habitat. After years of fireflies stories, I was hungry for firefly facts.
I passed the family room window. Jim had fallen asleep in front of the news. A self-described mosquito magnet, he was hard to lure outside at night.
A smaller light burned at the basement window. I hesitated. Considered.
My son had become less visible and communicative these days. The pandemic had shifted his territory to the basement, where he had set up his computer for Zooms and gaming. Although the world had mostly resumed its rhythms, G still seemed stuck. His friends did too. It was hard to get them to gather in person. They seemed to prefer yelling at each other on a Discord server to grabbing pizza in town. In addition, spine surgery and a follow-up procedure had led G to spend longer stretches of time downstairs while recovering. It felt like he’d been in that basement for two full years. As long as firefly larvae. The thought of how long it took fireflies to emerge from the soil hit home.
But G had been medically cleared for all activities. Here was his chance to have a firefly summer, running around the yard. And the basement, despite our efforts to make it cozy and to monitor online activity, no longer felt safe. The Internet, the news, toxic social media posts, were leaking in through the computer.
I wanted him out.
I don’t know what I expected as I headed downstairs. That we would run around the yard with jars? Five years prior, we’d gone turtle tracking at night with biologists. We’d fostered baby turtles together in our guest room. Two summers ago, we’d saved a baby robin that had fallen from its nest and reunited it with its parents. Was it too late to make another memory together?
I clung to hope. And a flashlight. G liked to game in the dark. It made him grumpy when I startled him by switching on the ceiling lights.
“Hey,” I said.
Click click click click, went his keyboard.
“Hey!” I blinked my flashlight to get his attention.
“Oh. Hey.” Click. His skin glowed green from the screen.
“Want to come outside and see something?”
Click click. Pause. Clickety-click.
“It’s really cool,” I added in a chirpy voice.
G sighed and took his headphones off. He followed me outside.
I hardly dared to breathe for fear of breaking the spell. “See?” I said with a grand gesture.
His smooth face, in the moonlight, registered pure boredom. He stifled a yawn.
Darn it. Where were the fireflies? “It might be easier to see in the backyard,” I suggested.
We stood shoulder to shoulder. I’d never been so aware of his height before. Or the passing of time. We were down to a handful of summers at home.
I looked up, wishing for a shooting star. I needed a show. I needed to keep him here. To plug him back into nature, the world. All I saw was air traffic. One plane after another, winking above the trees. Why so many?
“Oh! Look!” G suddenly exclaimed, pointing straight ahead.
A light flashed at eye level. Once, twice. Gone.
“What was that?” he asked.
I grinned. “Fireflies,” I said. “As are the ones up there.” I pointed. The airplanes, I now realized, were fireflies, darting among the tall pine trees. I’d never looked so high.
We watched in silence. Some even seemed to approach us, as if curious about us, too. Would they see us as two creatures? Or one?
“So I’m doing this community science thing for Tufts,” I said. “Help me count?”
He shrugged. But he stayed. Together, we counted eleven to fifteen fireflies in our first cycle, most with a double flash. We counted eight in the second cycle, half double flash, half single. And in the third cycle, five, with only single flashes. We went back in, to our separate computers. I logged the data. G went back downstairs to his game. We hadn’t seen a lot. But it was real data. Someone out there would see it.
I did Firefly Watch through the end of July, mostly alone as G’s glow of excitement faded. I wondered what messages the fireflies were sending to humans. I decided they were telling me to pay better attention to their fragile world.
I had started off the summer preoccupied with my own fragile world. I’d felt despair over how we can’t take certain rights for granted, or expect safety in our community spaces. Yet fireflies face a precarious environment every day. And they’re still here. For now.
The backyard conservation steps I’d been reading about suddenly made more sense. As a steward of this land, I could host generations of fireflies. I could turn off lights. Mow less. Leave leaves. Not fertilize the lawn. Not have a lawn.
But I could do even more.
When friends came for dinner one evening, a flash of light streaked by the window. “Did you know we have fireflies here?” I asked.
“Maybe we have them in our yard too!” their daughter exclaimed.
“I used to catch them in jars,” my friend said with a wistful expression.
We traded firefly stories. I told them about Firefly Watch. They signed up the next day.
I’ve noticed how faces soften, eyes light up, at the mere mention of the word firefly. Whether we’ve grown up seeing them in fields or in pages, these charismatic insects spark feelings of nostalgia, magic, and wonder. Firefly facts are important. But stories are powerful too. In sharing our firefly stories, we can connect with others and ignite change. If more of us are out there looking for these flashes in the dark, the fireflies can count on us to protect them and keep their story going.
By August, I saw fewer flashes. Then none. Adults, I learned, live two to three weeks, so I’d witnessed their final communications. Yet I didn’t feel sad. Eggs had been laid. Larvae would hatch in three to four weeks and feed until the end of summer. Then they would hibernate in tree bark, rotting vegetation, or soil, to re-emerge in the Spring.
The fireflies had gone dark for now. But I’d seen hope while observing their messages. Hope that matches were made.
I also saw hope when my husband laced up his shoes one evening and joined me outside. We can change our behaviors. Small changes count.
And I saw hope in my son’s increasing communications.
Hey, I texted G one afternoon. Ginormous praying mantis in the garden. Come see?
A pause.
Three dots.
His answer: K.
I smiled at the sound of his feet on the stairs, as he ran to join me in the light.
This essay originally appeared in 2023 as part of a Book-Based Interactive Installation in an art exhibit, Reimagining Conservation, curated by the organization Creature Conserve in partnership with Swale House (NY) and the Urban Soils Institute.