LINVILLE, N.C. (AP) — It would be easy to call it magical, this river of pulsing yellow-white light that washes waist high across a woodland floor.

It is tempting to say — as watchers sometimes will — that synchronous fireflies speak to us somehow.

And we do heed their call, drawn by the thousands to stare and to sigh at their sparkling nocturnal pageant every spring.

But these strobe-light dispatches in the dark are not for us.

Lightning bugs — all of them, not just the sought-after synchronous species so recently unveiled at Grandfather Mountain to a wide-eyed, desperate-for-a-glimpse public — have crucial work to do.

This is their end game. This is survival of the species.

This is a dramatic, illuminated mating call from the fast-flashing males — six or seven or sometimes eight swift sparks from the air, their neighbors catching the rhythm and spreading it across the night. Females, less populous and less frenetic, respond in their own time with two quick bursts, usually from ground level.

The result is an hours-long phenomenon of brilliant light, sometimes sparkling, sometimes soaring through absolute darkness.

“I’ll never forget it,” says Quin Tarry, who drove from Durham to see the fireflies in action at Grandfather Mountain on June 26. “To watch nature taking place like that, it just blows my mind.”

John Caveny, director of education and natural resources with the Grandfather Mountain Stewardship Foundation, has more opportunity than most to marvel at North Carolina’s great outdoors.

He describes the experience of watching synchronous fireflies this way: “I can count on one hand the number of times I’ve been held speechless by something in nature, and this is one of them.”

The dance that dazzles observers is the lightning bugs’ biological tool for locating one another during their short adult lives. They live less than a month in this fiery, flying form — after spending an entire winter or more as larvae, feeding on snails, slugs and the like. So time is short.

It’s a happy coincidence — for us, though maybe not for the rarest of the lightning bugs — that their courtship ritual, this not-quite-synchronized shimmer under the trees, creates a kind of real-life enchanted forest.

The synchronous firefly spectacle and others like it attract hordes of humans to dark mountain passes around this time every year.

When Grandfather Mountain opened ticket sales for the nature park’s first-ever June viewing of the lightning bugs, the firefly fervor was intense enough to crash the website. Some 11,000 people clamored for one of 600 spots.

In the Great Smoky Mountains National Park, tens of thousands a year enter a lottery for a chance to see the famous fireflies put on their annual show. Only 800 spots are awarded for eight days in April and May.

In recent years, when the lightning-bug-loving public discovered a population of blue ghost fireflies, a scarce species of the tiny twinkling invertebrate, the results proved perilous.

Dupont State Recreational Forest near Brevard saw scores of nighttime tourists descend onto its most popular trails during the blue ghost mating period in 2015, many of them venturing off trail for a better look at the blue-glowing bugs. In the process, they damaged the habitat the vulnerable blue ghosts depend on.

“Basically, Dupont was overrun with people at night,” says Stephanie Bradley, education and interpretation manager at Transylvania’s County’s FIND Outdoors — where blue ghost firefly tours sell out within days come the spring viewing season.

“People were walking off the trails to get to them. They were stepping through the leaf litter, disturbing the habitat and killing females, which can’t fly.”

‘What’s out there?’

You don’t have to win a lottery to go outside and see something amazing after dark.

Something is going to glow this year — might be glowing right this minute — in your backyard, or pretty close to your backyard.

The common eastern lightning bug — sometimes called a big dipper — puts on its own show in spring and summer. You’ll recognize them at dusk by the J-shaped pattern they fly as they shine their yellow-green light.

Watch closer to the ground and in the grass for lighted female responses.

Pay attention and you might find different species of fireflies based on their different flash patterns.

The big dippers shine around 4 seconds apart. Some will only light once every 10 seconds. Others emit two bursts every 5 seconds or so.

The daring “flash bulb” firefly looks exactly like it sounds. And it has the added benefit of a chilling backstory. The “femme fatales” can mimic the flash patterns of others and, once they have unsuspecting cousins in their clutches, eat the other species. (Some scientists say that’s likely less because of hunger and more out of a desire for consuming a certain chemical that protects her and her young from predators.)

Near her home in Iron Station, Mitzi Patton caught sight of a fast flickering beetle a few years ago and followed the glow to a ridge where she’d never paid much attention before.

“I looked up and it was a sea of all these little flashing lights,” she says.

It turns out Patton had discovered a pocket of “snappy syncs,” a species of synchronous lightning bug known for its near-constant nighttime blink during the late spring mating season.

“It’s not something you just see. You feel it inside you, the magic of all that happening,” she says, “… and what has to happen in the universe to make all these little lights glow at once.”

North Carolina boasts at least 30 to 40 species of firefly, according to researchers.

“So there’s always that sense of ‘What’s out there?’” says Grandfather Mountain’s Caveny.

“It helps you be motivated to get outside, even if it is nighttime. … Once you kind of get used to it, you’re just going to see a different world.”

In his view, the lightning bug — a symbol of so many childhoods — is the perfect conduit for connecting with the outdoors.

“Most everyone, if they grew up in the South for certain, has spent time running around in a field or in a yard, catching lightning bugs and putting them in a Mason jar,” he says.

‘Things … up against them right now’

In lightning bug conversations, almost as common as the Mason jar memory is the recognition that we don’t see their lights in the same numbers now that we saw in our collective childhoods.

Part of the answer could be that grownups — at least those who don’t luck into a golden ticket for one of the region’s public viewings — don’t spend much time in the yard as the sun goes down.

Even at Grandfather Mountain, staffers didn’t realize a show quite so spectacular was playing out in the woods after workers went home.

But fireflies are decidedly a species of concern, Caveny says. They’re not on any endangered species list, but it’s easy to see the threat.

“There are quite a few things that are up against them right now,” he says.

More firefly habitat — think forested areas and open fields — is being developed for residential and commercial use.

Pesticides and herbicides affect all invertebrates — so lightning bug populations in agricultural areas could be suffering from the continued use of chemicals.

Light pollution is also a major enemy of the city and suburban firefly.

“As these developed areas are spreading out and there are night lamps and streetlights and stoplights and a light on every corner, it affects their ability to find each other and be able to mate,” Caveny says.

“So they’ll either move off to another area or become locally extinct in certain areas.”

Cutting down on unnecessary light outside your house — floodlights that shine all night long, he’s talking to you — is one way to help ensure lightning bugs will stick around your yard.

Firefly fans can also employ a few of the tactics the pros at Grandfather Mountain use to encourage lightning bugs to stick around.

Picking an area where you don’t have to mow often or you don’t have to cut the grass too short will help with habitat requirements.

So will leaving patches of leaves on the ground come fall — though be careful not to pile leaves so high as to completely bury the lightning bug larvae already on the ground.

“Just providing an oasis for them, whatever that means. It may not be much,” Caveny says.

“But you’d be surprised what will show up — not just fireflies, but other pollinators, bird species, just different critters that you may not commonly see — when you leave a little piece of your property available to kind of get wild.

“It’s really special to see.”

It would be easy to call it magical.