On a chilly Friday night in early spring of 2013, four men and three women meet in a dimly-lit alley next to Manhattan’s City Hall Park. They are dressed against the unseasonable thirty-degree chill, in puffy jackets and protective working gloves with worn-down fingertips. With them are four small dogs on nylon leashes.

Richard Reynolds, a bald, husky business analyst from New Jersey, stands at their center, a head taller than anybody else, in an outfit made up of varying shades of khaki. In one hand he grips the wooden head of a long black cane, in the other a thin nylon leash, at the end of which is a ruddy brown dog named Dudley, a squat, short-legged Norfolk terrier with baleful brown eyes.

Reynolds surveys the scene—the dogs and their owners huddled in small groups along with Reynolds’s cameraman, Jeff Formosa, who would upload the night’s footage onto YouTube. Reynolds tapped his cane on the ground.

“Alright then,” he says. “I guess this is it. Let’s go.”

Quietly, the group steers their dogs across Chambers Street west of the park, Reynolds leading the way. Susan Friedenberg, a dog breeder from Staten Island, brings up the rear with her spotted auburn cairn terrier named Tanner. Reynolds stops at the opening to a cobblestoned side street while the others bring their dogs around to the back entrance of Theatre Alley, which George Washington once used as a private entrance to the Park Theatre.

Staring at a bulging garbage bag resting against a pole in the scaffolding, Reynolds raises his cane just an inch above the ground. Then, with a booming “HO!” he releases Dudley. The terrier shoots into the alley towards a massive pile of garbage bags against a wall. Reynolds waves a hand out to signal Friedenberg, and in the next moment Tanner is streaking down the path too, gaining on Dudley with every step. They jump on top of the mountain of trash, clawing at the bags as their owners run after them.

Reynolds seizes a plump white bag, spattering droplets of brown liquid against the aging brick. Dudley lunges where the bag had been, as shrill squeaks fill the alleyway. Panting, Dudley emerges from the pile, his jaws wrapped around something that he dragged across the cobblestones. Reynolds grabs the dog by its collar and crouches down beside it.

“Stop munching on the head,” he says.

Reynolds stands up slowly, holding his hand up to the light. Dangling from his thumb and forefinger is a limp, lifeless rat, its fur matted with blood.

***

Richard Reynolds is not the “rat guy.” Yes, he has a closer-than-normal connection with rats. Yes, he sees a lot of them, even spends his Friday nights seeking them out. But if you ask him, as many do, he’s not “that rat guy.” He is, he insists, a verminologist— the best verminologist in New York City, he is quick to add.

But Reynolds knows a lot about rats. He knows that a rat’s gestation period is twenty-three days, its average litter size is ten to twelve, and mortality after birth is about a third. Start with two rats today, he tells me, and you’ll have 24,000 in a year.

“Its been said that in New York City, you’re never more than thirty feet from a rat,” Reynolds, leader of the Ryder’s Alley Trencher-fed Society (R.A.T.S., for short), said. “If that’s not literally true, then it’s pretty near.”

Reynolds leads his assemblage of trackers and undersized hunting dogs to alleys in Brooklyn and the Lower East Side, seeking the massive piles of garbage that businesses put out on Friday nights. These stinking heaps harbor the most rats—the crew’s preferred quarry. The group’s main goal is to exercise their dogs’ natural instincts—terriers especially, they argue, were bred to hunt vermin over the past few hundred years. And helping to control the pest problem in New York’s alleyways doesn’t hurt, either.

“Our hunts, they suit both the places we hunt and it suits the terriers—they do what they were born to do,” Reynolds, a former foxhunter and dog show judge, says. “They love it, we get our kicks out of it.”

He commutes from New Jersey to City Hall Park for his Friday expeditions. His motley band takes requests from rat-weary residents and restaurant owners concerned by rats scuttling by their doorstep, which scare away customers.

Many owners administer Amoxcillin to their canine killers for several days before the hunt to ward off rat-borne illnesses. Pant legs duct-taped shut, they poke through trash piles with metal staffs and swing their flashlights side to side, eyes peeled for that soft, startling rustle that signifies the prey is close at hand.

“We depend on a certain amount of filth,” Reynolds says, stabbing a big black bag with the end of his walking stick. The group had moved on to Eden’s Alley, a few blocks away from the first hunting grounds. But the hunting was no good. Reynolds even walked the group up to his favorite spot, a two-by-two sliding red trap door built into the wall of a winding side alley years before to close a rusted-out hole in a metal plate. “That’s the rat door,” he says. “Through that door have passed gazillions of rats.” Mighty, a sleek black terrier on his first hunt, scratched at the door, sniffing its handle in search of one.

***

The brown rat, or Rattus norvegicus, is the most common mammal in New York City. They are incredibly productive—male brown rats may mate with up to twenty female rats in just six hours. Males have been known to mate with pregnant, juvenile and dead rats—and even other males, if there are no females around. The rat’s sexual appetite, combined with the female’s ability to conceive just hours after birth, are what make the rodent one of the fecund in the animal kingdom.

Rats are skilled city dwellers: They can squeeze through a hole the size of a quarter, develop immunities to poisons, and are excellent swimmers. Some even catch fish. They can climb vertical surfaces and survive a thirty-foot fall without injury. They can cause damage, too—such as starting fires when they gnaw through wires with their sharp teeth, which are stronger than aluminum, and exert a pressure of up to seven thousand pounds per square inch. One study from Cornell University estimated that rats cause $19 billion in damage every year, the most of any introduced species in the United States.

It is impossible to chronicle the history of New York City without including its rats, which now number around 250,000. In the nineteenth century, the brutal sport of “rat-baiting” was popular in the city. At the infamous Kit Burns’s Sportsmen Hall on Water Street, men would gather to watch dogs thrown into wooden pits filled with rats, and bet on how long it would take for the dog to kill all the rats. In one iconic incident, a terrier killed 100 rats in just six minutes and 40 seconds.

More recently, journalist and author Robert Sullivan spent a year trudging through the rat-infested alleys of Lower Manhattan in order to write his book Rats: Observations on the History and Habitat of the City’s Most Unwanted Inhabitants.

“Rats live in man’s parallel universe, surviving off the effluvia of human society; they eat our garbage,” Sullivan writes. “I think of rats as our mirror species, reversed but similar, thriving or suffering in the very cities where we do the same.”

Sullivan’s yearlong foray into lower Manhattan’s rat world took him to some of the same alleys that Reynolds and his crew frequent. He describes his time spent observing rats in the city’s dirty, infested alleys, at one point detailing an encounter with the “Rat King”—a massive, foot-long beast with a curly tail.

New Yorkers love to tell such stories. There was the three-foot-long white rat killed by a Brooklyn man with a pitchfork in 2011 (it turned out to be a Gambian pouched rat, likely an escaped exotic pet). There was the time that mayor Rudy Giuliani appointed a ‘rat czar’ after the rodents were spotted on the porch of his mansion. There was even a photo that emerged showing a rat crawling over the face of a sleeping subway rider. But New York’s animal activists, who have spoken out against Reynolds’s rat hunts, argue that rodents should be treated better.

“Rats are sentient beings,” says Dena Jones, a representative of the Animal Welfare Institute (AWI), a nonprofit that pushes for legislation to reduce animal suffering. “They can experience pain and distress, just like bears, dogs, chickens and bulls, and killing them is not a source of amusement in a civilized society.”

Jones and the AWI argue the best way to restrict the rat population in cities is to control food sources rather than trapping or poisoning them, methods that they say are inhumane. “Like it or not, mice and rats are part of the urban landscape,” Jones says. “We can’t eliminate them entirely, and so we must learn to coexist with them, which we can do by minimizing the damage they cause.”

Exterminators have many techniques for dealing with the rat problem, poison foremost among them. A new approach, however, suggests using bait laced with birth control to keep their numbers down. The MTA hired the pest control firm SenesTech to test the technology in March. Animal activists support this alternative, arguing that it is a more humane version of rat control.

“The use of contraception in rodents has been researched over the past decade or so,” Jones says. “It may hold promise for addressing extremely large urban populations, but good sanitation will always be the primary—and most humane—approach to rodent control.”

When Hurricane Sandy walloped the city last year, rumors flew of evolutionarily superior “super-rats” breeding after the weaker rats died during the storm. While likely apocryphal, exterminators did see a huge spike in rodent infestations after the storm because there was so much debris littering the battered streets. The city’s 311 hotline was inundated with complaints from concerned homeowners, so much so that City Council Speaker Christine Quinn held a press conference to call for a $500,000 increase in resources to address the problem.

“We want to make it very clear to rats that they are not welcome,” Quinn said. “We are very open to all kinds of folks coming to New York City. We love immigrants, we love new New Yorkers, but we do not love rats.”

***

Reynolds and his crew consider their hunts to be a more humane alternative to typical pest control methods like glue boards and poison bait. “There are lots of worse things that people do to rats,” he says, back on the shadowy streets of Lower Manhattan.

The group has returned to its starting point at Ryder’s Alley. It is ten o’clock, and the moon reflects off tiny pools in the street with little dappled sparkles. Mighty, the black terrier held back by his owner, Jimmy, a Queens native with a thick accent, finally has his chance to hunt, and is doing so spectacularly. He’s already caught two; one a puny juvenile, the second a portly monster. When Mighty caught the second one, Jimmy grabbed it by the tail and twirled it around his head like a lasso, showboating for the cameraman. The group is in good spirits—Tanner had gotten two rats, too, one of which he and Mighty had fought over, each pulling at one end of the little creature until the rodent split in two right down the middle.

Tonight’s quarry is small compared to other hunts, during which the rat count can number in the dozens. But the group keeps at it, rushing up to the scuttling vermin, cheering on their terriers and scooping up the little lifeless bodies they leave behind.

“We usually hand ’em on a pole,” Reynolds says, picking up a rat, its intestines trailing across the ground behind him as he brings it over to a trash bin where he’s been depositing the corpses. “Tonight we’ll just throw ’em away.”

The final count is seven dead rats—a low number for the group. The dogs are dragging, and Astro has entirely given up, lying on the ground at Connie Formosa’s feet. Reynolds glances into the garbage bin, scowling at the small quantity. They leash the dogs and start to walk back toward City Hall Park, their tight-knit phalanx now a loose group of tired hunters. Jeff Formosa, packing up his camera, says he got some good footage of the hunt to post online that night.

“We’re trying to publicize, to get the word out there so we can raise money,” Reynolds says, tugging a sluggish Dudley along the sidewalk. “We’re trying to get pins—you know, like, buttons? We really want some buttons.”

Melissa Cronin is a Bay Area-based writer and Ph.D. Student in Ecology and Evolutionary Biology at UC Santa Cruz.