INNER MONGOLIA, North China — The Hulun Buir Grassland Station has a room dedicated to taxidermy. Here, owls, eagles, and foxes — the grand animals that live on the vast steppes near the Russian border — are preserved inside a glass cabinet. Perhaps fittingly, the bottom of the cabinet is reserved for scores of taxidermy specimens of another animal, one the reserve isn’t so keen on: the zokor.

Locals commonly refer to the small rodents simply as “rats,” but the zokor is a closer relative of hamsters. They’re covered in fluffy gray fur, and their vision and hearing are so poor that they are in effect both blind and deaf. But the animal is far from harmless. Zokors live underground, digging burrows with their long front claws — and destroying the grasslands’ root networks in the process.

“I hate them,” says Sirijima, a 55-year-old herdswoman of the Ewenki minority, who go by a single name. “My family hates them,” she reiterates. Sirijima’s family herds more than 400 sheep and 10 horses, animals that eat the area’s wild grasses. But a single zokor can turn a swath of grass into as many as 30 piles of soil overnight. Some herdsmen report their livestock breaking legs when they get stuck in the piles, and the mounds prevent herders from using machinery to cut the grass, rendering stretches of grassland unusable for animal husbandry.

Zokors and herdsmen have lived together on these lands for centuries, and unless snared in a trap — the most common way to catch zokors — the animals themselves are hardly ever seen. In the past few decades, however, climate change, drought, overpopulation, and unsustainable land management have led to the slow degradation of grasslands across China. By killing the roots of grass and other plants, the zokor, too, plays a role in this degradation.

The Hulun Buir Grassland Station, which falls under the local agriculture and animal husbandry bureau, monitors the ecosystem and manages conservation, but there’s little its staff can do to battle global threats like drought or climate change. The zokor population, however, can be controlled. In the past few years, the station has employed scores of “rat hunters” to cover the 150 million-square-meter area, and has instructed herdsmen on how to set up traps and kill the fluffy pests. The rule of thumb for the station’s rat hunters is to limit the zokor population to no more than 300 per hectare, but for the most part, the seasoned hunters respond to complaints from residents. Last spring alone, the hunters killed some 17,000 specimens.

“If there are fewer [zokors], we don’t need to control them as long as they do not affect our food production and our daily lives,” says Chaoketu, the head of the station. In recent years, they government has not shied away from taking strong action to control the zokor population. In 2010, tens of thousands of workers were dispatched to spray poison when a major “rat plague” threatened about 337,000 square kilometers of grassland — roughly the size of Germany.

The poison was effective, but it harmed the surrounding environment and other wildlife. Traps of all sorts are now the most widely used weapon against zokors. “When you set a trap, you have to put it in the main tunnel that [the animal] passes through every day,” explains Ma Changlong, the leader of a 40-strong team of rat hunters.

Ma says he can tell from the location of a single soil pile how the intricate network of burrows spreads underground, some as deep as 5 or 6 meters beneath the surface. Like humans, the zokor fashions itself a home with several chambers, each for a different purpose: living, sleeping, and defecating. Ideally, Ma and his team will manage to install the trap right by the zokor’s living room.

Although one hunter can catch up to 100 zokors a day, it requires a lot of legwork, as the traps must be set manually and checked the next day. To cover the vast area, the hunters rely on the help of herdsmen like Batumenghe, an Ewenki who lives two hours by car — through rugged pastures and hills — from the Hulun Buir Grassland Station.

“The soil piles affect horseback riding in the area,” Batumenghe says at his home, as two barking dogs run around a traditional yurt that he uses for storage. Most herdsmen in the area, both ethnic Mongolian and Ewenki, have moved into modern houses, decorated with images of wild horses and posters of Genghis Khan.

The 61-year-old has developed his own techniques to hunt zokors. Poison isn’t allowed anymore, but he’s created a trap consisting of a hook on a long string; once triggered by a zokor, the hook pierces the animal and pulls it out of the hole. “Tractor exhaust fumes can kill them as well,” he says.

Another method is to open up one of the soil piles to expose the burrow below and wait three to four minutes until the zokor comes up to patch the hole. All you have to do then, Batumenghe says, is stab the animal with a pitchfork. He kills at least 100 zokors each year: They make good dog food, he says.

Additional reporting: Li You; editor: Kevin Schoenmakers.

(Header image: Pest control worker Hu Sile catches a zokor in the Hulun Buir grasslands, Inner Mongolia Autonomous Region, Sept. 16, 2017. Shi Yangkun/Sixth Tone)