One Remote Island’s Battle Against Acid-Spewing Ants

At the world’s remotest nesting colony, the Crazy Ant Strike Team beats back its seabird-killing enemy with spray guns, poison... and cat food.

I’m crouched beneath a tropical koa tree on a 102-degree day, readying myself for the attack. Next to me, a woman in a bikini top and shorts sprawls on the ground; beside her squats a guy in swim trunks. Eight more twenty-somethings, all dressed for the beach, are scattered throughout the grove. Someone begins to dig, and soon everyone is pawing at the dirt. Within moments the black earth starts undulating, and a stream of caramel-colored ants erupts. The insect army spreads out, assessing the threat, swarming over rocks, fallen leaves, everything—including us.

At first they tickle as they zigzag up my leg. Then searing pain shoots through my knee as ants reach the coral scrape I’d gotten snorkeling the day before. “Hah,” snorts the woman next to me, looking up on hearing me gasp. “Feel the lava burn.”

These are yellow crazy ants. Crazies don’t bite. They spray acid.

Notorious invaders likely native to West Africa or perhaps Asia, crazy ants cross the high seas on driftwood or as stowaways on vessels, and they have infiltrated many Pacific islands. Once established, crazy ants storm over any ground-nesting seabirds in their path, blinding and maiming those that don’t flee. For years they have threatened to turn this place, called Johnston Atoll, into an avian wasteland.

Of course, to the casual observer, Johnston, which lies some 700 nautical miles southwest of Hawaii and is surrounded by 750,000 square miles of ocean, might already qualify as a wasteland. Known officially as the Johnston Atoll National Wildlife Refuge, it is a cluster of four smallish uninhabited islands (two modified natural formations, two man-made by dredging). Just getting here from Honolulu takes three days aboard the 185-foot diesel vessel Kahana, thanks to bureaucratic red tape that has rendered the island’s perfectly serviceable Air Force-grade runway off-limits.

But this abandoned nubbin of land happens to be home to hundreds of thousands of nesting seabirds, among the remotest gatherings on earth. Thus it is also home to the Crazy Ant Strike Team, a U.S. Fish and Wildlife Service project designed to protect them. Every six months a new five-person crew rotates in, sets up camp—their only links to the outside world a 1990s-quality Internet connection and a satellite phone for emergencies—and gets down to the business of killing crazies.

Volunteering for a stint on Johnston is like taking a vow of silence, or maybe poverty. Once the new arrivals hit the beach, the departing team has just five days to pass on their knowledge, and the scientific stuff—tracking down crazies to kill or experiment on, conducting bird surveys and other fieldwork—is only part of the challenge. In less than a week the replacements have to learn to survive on their own. There’s no freshwater source or plumbing on Johnston, no indoor toilets, and no option for bathing or doing laundry other than the ocean, where sharks are a given. This former military base also happens to be a minefield of hazardous waste. Camp, for instance, is located between a plutonium landfill and a former Agent Orange storage site; don’t, the rookies are told, go digging in either. “Nobody wants three-armed babies,” says Allison Griffin, an outgoing CAST member.

This morning we are learning how to prepare ant colonies for insecticide studies. The air under the koa is thick with formic acid; it smells like urine and makes our eyes sting and our mouths taste like burning plastic. “Ew, ew, EW,” shudders rookie Caitlin Dudzik as ants crawl into her hair. “You’ll get used to it,” Jane Sheffer assures her, but Dudzik looks dubious. The old guard casually pick out the giant queens and secure a dozen in a Tupperware container. Everyone shakes their hands over a large bin to collect workers, and thousands pile up in minutes, the writhing mass unable to climb the walls painted with a slippery substance called Fluon. The lesson ends with a mandatory dip in the ocean—not to clean our dirt-streaked bodies but to drown any hangers-on and prevent them from spreading to ant-free areas, one of the strict protocols nine CASTs have developed over the past five years.

Those teams have been far more successful than anyone anticipated at knocking back the enemy, and 14 species of seabirds now nest on the ant-free parts of the island—in insane numbers. The air itself has the pungent, musty odor of guano. The midday sky is a swirl of wings: Piratical Great Frigatebirds dive-bomb shearwaters and steal their fish; colonies of thousands of terns and noddies cover the island’s eastern tip, blasting a cacophony of caws and screeches for a mile. There are signs of death, of course, as in the severed head of a White Tern (prey for a Short-eared Owl that likely flew thousands of miles from mainland Asia or North America), but Johnston is boisterously, overwhelmingly alive.

Even in the quieter areas, the hostile squaaaaawks of Red-tailed Tropicbirds nestled in the brush are a startling reminder that this turf belongs to the birds. The eight-foot-tall pluchea bushes are bursting with Red-footed Boobies ranging in size from eggs to fluffball chicks to almost-fledglings to full-blown adults, all perched among the limbs like ornaments on a Christmas tree. This asynchronicity—the birds’ ability to breed any time of year—is just one of the bizarro aspects of life in the tropics. “The closer you get to the equator,” says Lee Ann Woodward, a scientist with the Hawaiian and Pacific Island National Wildlife Refuge Complex, which includes Johnston, “the weirder it gets.”

Insects waging chemical warfare on seabirds certainly fits the weirdness bill. The ants are persistent buggers, and the threat of the weakened army rising up again is a constant worry. “The thought that just one queen and some workers could spawn a super-colony,” says Jenny Howard, the outgoing CAST leader. “That’ll keep you up at night.”

Despite its remote location, Johnston Island may be one of the most manipulated and abused sites in the world. The Unites States annexed it as a guano island in 1859, and the waste was harvested for fertilizer until 1926, when President Calvin Coolidge established the atoll as a federal bird refuge. In 1934 President Franklin Roosevelt placed Johnston under U.S. Navy control, while keeping its status as a refuge. The Navy built a seaplane base, airstrip, and refueling facilities that proved critical during World War II. The U.S. Air Force, interested in building a secret missile base, took over in 1948, expanded the two existing islands, and created two new ones. Seen from the air, the main landmass looks suspiciously like an aircraft carrier.

In the years since, just about any group that has anything to do with defense seems to have had a presence on Johnston, from NORAD to Raytheon. The atoll’s colorful history includes nuclear weapons testing, space recovery projects, and chemical weapons storage and disposal. In 1985 Congress ordered the Department of Defense to eliminate the country’s stockpile of chemical agents and munitions. By 2000 the Army had destroyed 400,000 rockets, projectiles, bombs, mortars, and mines—as well as 2,000 tons of nerve agents—on Johnston alone. Four years later the military completed razing the island and removing most of the infrastructure, including the apartment buildings and neat homes on palm-lined streets that housed about 1,200 people. Now the Air Force retains jurisdiction over the atoll, although the USFWS oversees the natural resources, fish, and wildlife.

On Main Street today, koa trees and pluchea bushes burst through the pavement. Warning signs with messages like “Restricted Area: Use of Deadly Force Authorized” litter the ground. Ghosts of former structures persist in crumbling concrete slabs and staircases to nowhere. A windowless, hurricane-proof, radiation-proof building that was too sturdy to demolish—the former Joint Operations Center—stands like a creepy sentinel on the eastern end; vegetation is slowly devouring it and the dozens of sealed chemical storage bunkers that remain, like Mayan ruins cloaked by jungle.

Despite Johnston’s toxic legacy (in addition to the plutonium, there’s plenty of dioxin and asbestos, too), Woodward, who oversaw the closure and cleanup of the Air Force base for the Fish and Wildlife Service, hoped that the place would prove to be a paradise for seabirds once the humans were gone. After all, at least it wasn’t plagued by invasive rats, which have decimated so many Pacific avian populations. No such luck. In January 2010 Woodward discovered the crazy ant invasion when she and a colleague, a seabird biologist, spent a few days on Johnston. “The ants became our top priority,” she says. “We drove around the island doing scuff tests to mark the perimeter. The ants are so territorial you just scuff the ground with your shoe and they come up to investigate.

Woodward found that the crazies’ core territory might as well have been scorched earth for birds. The two dozen or so Red-tailed Tropicbirds in the infested zone looked like zombies. They were sluggish, twitching as ants crawled over them. Their acid-burned eyes were swollen shut and blinded, and their previously brilliant white feathers singed brown. And it wasn’t as though the local birds were all that delicate—Woodward saw tropicbirds nesting on the asbestos dump—but in this weakened, sightless condition, Woodward figured, they would starve to death, eventually providing a feast for the crazies. “I knew we had to do something or the ants would take over the entire island,” she says. “We’ve interfered and fucked up the ecology of these islands so much over the decades. We couldn’t just leave the refuge to die.”

On the long trip back to Honolulu, she and her colleague began devising a counterattack.

Woodward is five-foot four, with a short, no-nonsense haircut and, as she puts it, “no patience for bullshit.” She is brusque, tenacious, and fiercely protective of her people. “Lee Ann is not someone you’d want to be stuck with on a deserted island, but you sure as heck want her looking out for you from headquarters,” says one employee, who wished to remain anonymous. She is a woman who gets things done.

For years Woodward had wanted to put a team on the island, if only to discourage illicit human visitors from stopping by and inadvertently dropping off invasives. (Pacific islands have been overrun by more than 50 exotic ant species alone. Johnston itself is now home to several other ant species, though none nearly as destructive as the crazies.) After her crazy ant revelation, she finally had a good reason to set up a camp. In May 2010 she got the go-ahead to put together the first CAST and hired Stefan Kropidlowski to lead it, with the promise to underwrite his master’s work. In August he and three volunteers were dropped off with tents, propane, a generator, a rain catchment system, mounds of canned and boxed food for themselves, and a hell of a lot of poison.

Their surveys revealed that crazies—named, by the way, for the erratic way they move—had invaded roughly a fifth of the island, an area the size of nearly 100 football fields. While many ant species build colonies with a single queen, crazies build super-colonies made up of massive nests that contain hundreds of queens each. The vast number of queens, all sisters seemingly immune to sibling rivalry, enables a single colony to expand its territory by up to 100 feet a day.

Once they knew where to strike, Kropidlowski put out commercial bait pellets that had successfully controlled yellow crazy ants elsewhere. But between the climate and the insects themselves, nothing was easy: Most of the 6,000 baiting stations had to be replaced multiple times because of heavy rains. And the poison didn’t work. Ants carried away the pellets, but the team saw only a 50 percent decline in numbers. “We should’ve seen a 90 percent reduction,” says Kropidlowski. “I’m convinced someday we’re going to find a huge stockpile of uneaten pellets.” They gave up on the first insecticide in January 2011, and tried a second one. This time ant numbers actually went up.

“It was miserable and frustrating,” recalls Kropidlowski. “You have to wear dedicated baiting clothing—disposable scrubs, goggles, shoes and socks, long sleeves—and it’s so, so hot. We had to make new insoles from Rite-in-the-Rain notebook covers because we wore holes in our shoes.” (It was the only time a team stayed more than six months: “They were just too exhausted and they reeked to high heaven by the end,” says Woodward.)

The second strike team scratched the commercial bait traps and began tinkering with their own noxious blends. The recipe had to contain sugar, to attract workers, and protein, which sustains queens. The team spent half a year testing peanut butter, honey, Spam, corn syrup, and cat food, even digging into their own food supplies to find ingredients for palatability trials. “The ants went nuts for squeeze Velveeta from the mac-and-cheese dinners,” says Kropidlowski, who reupped for a second tour of Johnston. “But they don’t sell it by the vat, and I was not going to melt down blocks of it. It’s disgusting.”

 Just as its stint ended, the second team hit on the right combination: Friskies Ocean Whitefish seafood pate and dark Karo syrup, laced with a pesticide. Kropidlowski returned with the third CAST and refined the recipe. The ant population dropped by 99 percent. Within weeks—yes, weeks—the number of Red-tailed Tropicbird nests in the treated area grew from 24 to 524. Today more than 5,700 tropicbird pairs nest on the island, or nearly half the estimated global population. The project has been so successful that the USFWS is testing a similar recipe on crazies terrorizing Mokuauia, an islet off Oahu.

“I was skeptical, but they’ve made incredible progress,” says David Oi, a U.S. Department of Agriculture research entomologist who advises the project. “Success in this case might not mean eradication. If you bring the numbers down enough, I think you can keep the ants in check and they won’t rebound.”

"This looks like a demented cooking show set in an insane asylum, starring murderers,” says incoming CAST member Kyle Davis. His expression is half disgusted, half amused as he mixes bait for the first time. We’re in the decrepit former education center, which feels like something between a bomb shelter and a scrap yard: A useless air conditioner lies on the ground beside an overturned chair; frayed wires hang from a coverless fuse box. Guano smears the floor (two Wedge-tailed Shearwaters are stubbornly resisting human efforts to keep them from nesting here), and everyone is sweating in their long-sleeved Tyvek scrubs, even though the backs have been slashed for ventilation. The dried bait splatters on the outgoing team’s well-used uniforms look remarkably like bloodstains.

Kristin Brunk, counting down the minutes to her departure, shows the rookies how it’s done, belting out Lady Gaga as she runs a drill with a three-foot auger attachment. In a 5-gallon bucket she’s combining the elements of CAST’s irresistible elixir: 6 liters of water, 8.25 cans of Friskies, 4.5 bottles of dark Karo syrup, 150 milliliters of xanthan gum, and 72 grams of the insecticide Provaunt. The mixture is the color and consistency of a chocolate milkshake and gives off a sweet fishy odor.

Once the team has eight buckets of the stuff, they take up spray guns capable of holding about a liter of the slime at a time. Later, as I watch the begoggled crew spray the bait in the infestation zone that persists mid-island, something niggles. It’s too quiet. Tropicbirds and frigatebirds are soaring and calling far overhead, and there’s an occasional far-off bark from a booby, but no birds are nesting here. It’s a sobering glimpse of the fate that might have befallen the entire island had the USFWS not intervened.

 While some people—maybe most—would run screaming at the thought of signing up for a stretch on Johnston, there’s no shortage of applicants. The hires are usually recent college grads with fieldwork experience, and Woodward and her staff rely heavily on a multi-hour interview to make the final cut.

“That’s where you really get a feeling for someone,” says Howard, the departing CAST leader. “One guy that looked great on paper totally creeped me out on the phone. When we asked him to describe himself, he led with: ‘I’m an only child. I murdered my twin in the womb.’ Uh, no, thanks. I am not spending six months on an island in the middle of the Pacific with you.”

The outgoing team last summer consisted of four gals and one guy, Ben Donnelly. Odds of a romantic interlude were seemingly in Donnelly’s favor, but the women apparently came to view the wiry 21-year-old as something of a little brother. Taking inventory of the medical supplies one afternoon, Howard says, a bit ruefully, “Two packs of condoms. Didn’t need those.” (For his part, Donnelly, who by this point looked like a Survivor contestant with his sun-bleached mane and long beard, had this to say about living with all ladies: “There were a lot of tears. I grew up on a dairy farm with two brothers. There wasn’t crying.”).

Before the Kahana left Honolulu and again on Johnston, Woodward tells the incoming team they’re stuck on the island “unless life, limb, or vision is threatened.” If there’s a hurricane or typhoon, they’re to take refuge inside the indestructible four-story building; in case of wildfire, they should grab the satellite phone and jump in the ocean. When a doctor is needed, the leader contacts a medical service and then fills the prescription from the island’s well-stocked supply cabinet, which includes Valium and antipsychotics.

When they aren’t combating crazies, the crew keeps busy with the green sea turtle count, a near-shore fish and invertebrate survey, bird banding, Ant Farm insecticide trials, and clearing vegetation that threatens to consume the unused runway. And there’s the groan-inducing, weeklong, full-island tropicbird survey, which entails counting every nest, using a long stick to lever up thousands of adults to see if there’s a chick or egg underneath them. “There were a lot of cranky birds and humans,” says Howard.

Then there are the camp chores. Everyone gets a private eight-man tent with a queen-size blow-up mattress, but everything else is communal. Team members take turns cooking meals in the Ant Cave, a former bunker that houses a kitchen with a gas stove, refrigerator, freezer, and dozens of shelves crammed with food; a computer lab; and a library with everything from Carl Safina’s nature books to John Grisham’s legal thrillers. The island has three compost toilets, a generator, a John Deere Gator, 10 bicycles, solar panels, a rain catchment system, and a garden to tend.

Keeping it all running takes an immense amount of cooperation. “Spend six months on an island with only four other people, and you have disagreements, you have misunderstandings, people sometimes drive you crazy,” says Griffin. “When we were applying, they asked what our pet peeves were. What we couldn’t stand. I couldn’t come up with anything. Now I know: It’s Ben dragging his goddamned feet.” She never mentioned it to him, though. “You have to let the little things go, or we’d tear each other apart.”

That’s the kind of advice they’re passing along two nights before the Kahana sets sail. We’re on the western tip of the island, far from the ship’s lights, watching a meteor shower. More specifically, we’re at the shark chute, where the crew dumps its food scraps; those attract fish, and the fish attract tiger sharks—record-holders for the most attacks on humans, after great whites—so everyone minds Woodward’s warning not to get too close to the crumbling edge.

Tomorrow the departing crew members will vacate their tents and move onto the boat for their last night on Johnston. Tonight, as streaks of light shoot across the inky sky, the air is filled with quiet conversation about what’s to come, for both those facing months on this remote island and those about to return to civilization.

Someone starts to ask the group a question, only to be cut off by the scratchy yip of a Short-eared Owl. As our murmurs start up again, the eerie wail of a single Wedge-tailed Shearwater pierces the night, echoed by more shearwaters lodged in their underground burrows nearby. We’re outnumbered. Here, on the edge of a former Agent Orange stockpile site, on an island sculpted and tainted by humans, the birds rule, day and night—just as they should. We shut up and listen.

Alisa Opar is the articles editor at Audubon magazine.