Everyone’s Least Favorite Rodent Is Cleaning Up the Lethal Leftovers of War

Land mines kill thousands every year—but rats are being trained to save lives by sniffing out the scent of explosives.

(Photo: APOPO/Instagram)

Apr 11, 2015· 2 MIN READ
Vince Beiser has reported from more than two dozen countries for Wired, Harper’s, The Atlantic, Rolling Stone, and others. In 2014 he won the Media for Liberty Award.

Hidden underground in dozens of countries all over the world, land mines left behind from long-finished wars kill and injure some 4,000 people every year. Finding and deactivating all those concealed explosives is difficult and dangerous. But today, people in many mine-plagued nations are getting a hand from an unlikely ally: rats.

From its headquarters in Morogoro, Tanzania, APOPO, a Belgian nonprofit organization, trains African giant pouched rats to literally sniff out land mines. The highly intelligent critters have a sense of smell as keen as a dog’s, enabling them to detect the scent of explosives even when they’re underground. Too small to set the mines off, the rats point them out to their human handlers, who then check and clear the danger area. The organization works in six African and Southeast Asian countries and says it’s have helped clear millions of square meters of land and destroyed nearly 49,000 land mines.

(Photo: APOPO/Instagram)

“The idea of using rats to sniff out mines came to APOPO’s founder, Bart Weetjens, 20 years ago as he read an article about gerbils being taught to recognise the scent of explosives,” reports The Guardian. “Weetjens, who as a boy bred hamsters, rats, mice and gerbils, began to wonder which rodent would best serve those whose limbs and livelihoods are threatened by landmines.”

He settled on the African giant pouched rat, Cricetomys gambianus—a rodent found in abundance in sub-Saharan Africa. The rats are trained using a five-step process that includes scent condition and scent discrimination, allowing them to recognize the correct scent out of a large sample. Today, the group fields dozens of the immodestly named “hero rats” in former war zones.

The practice of killing people with buried explosives dates back to at least 1277, when the Chinese defended themselves from invading Mongols with bombs hidden in the ground. But it was World War II that really brought them into common use—more than 300 million mines were sown in that conflict. Both Allies and Axis generally mapped out where they planted their mines, making it easier to find them after the fighting finished. But that wasn’t the case in many of the conflicts that erupted in Europe’s former colonies in Africa and Asia in the 1960s, when cheap land mines became a weapon of choice. Guerrilla fighting forces often didn’t bother keeping track of where they’d planted explosives. That’s why today, even though most of the world has signed a treaty banning the production and use of land mines, there are millions of explosives still hidden in the fields, forests, and roads in dozens of countries.

(Photo: APOPO/Instagram)

So every helping hand—or paw—is welcome. Still, some de-miners are unimpressed with the hero rats. They complain the rodents’ legs are too small to walk regular patterns in overgrown fields; that means you have to trim vegetation and attach the rats to a string to literally keep them in line. “You need to spend so much time clearing space, you’re better off doing it manually,” British army vet and professional de-miner Andy Smith told Pacific Standard.

Good thing, then, that APOPO is also training rats to use their mighty noses to detect tuberculosis. “APOPO says its rats have so far identified more than 7,000 tuberculosis patients who were missed by human technicians, potentially halting more than 24,000 further infections,” reports The Guardian. One way or another, the group is determined to live up to its tagline: “We train rats to save lives.”