Linda Poon is a staff writer at CityLab covering science and urban technology, including smart cities and climate change. She previously covered global health and development for NPR’s Goats and Soda blog.
All they’re asking for in return are some treats and a bit of love.
Rats are not beloved. They frighten subway passengers, infest millions of homes across the U.S., and their beady eyes are said to be those of the devil. The ones in New York City are so threatening that the government recently declared war on them.
But in Cambodia, the sight of giant rats scampering along grassy fields is a welcomed one. That’s because they’re there to sniff out land mines.
“They have a very keen sense of smell and there is no problem for them to find the land mines,” says TeKimiti Gilbert, head of mine action at Apopo, a Belgian organization that trains rats for humanitarian purposes.
Apopo’s African giant pouched rats—or “hero” rats—are being trained to sniff out tuberculosis and detect TNT vapor in the ground. They’re bred and raised at the organization’s headquarters in Tanzania, and those used to detect land mines have already worked in Mozambique and Angola.
Most recently, a group of 15 rats deployed for training in Cambodia, a country that’s still feeling the effects of a decades-long war. It’s one of the most heavily mine-polluted countries in the world, with an estimated 4 to 6 million uncleared land mines and other explosive still in the ground. Altogether, they’ve injured and killed more than 64,000 people.
The rats have been working with local trainers at the Cambodian Mine Action Center since April. Each is attached to a harness tied between two handlers, and it searches the ground for deactivated land mines as it runs from one hand to the other. Oil filters, tuna cans, and other objects are buried in the dirt to create confusion. If the rats sniffs out the right thing, they get a treat, usually fruits or nuts.
Once training is complete, the rats will be used in areas that are deemed low- or medium-threat. They’ll help officials confirm that a space is indeed mine-free. Apopo hopes to put 10 more “hero” rats in Cambodia, if funding allows.
Gilbert acknowledges that not everyone is as optimistic as his organization. “There is a level of skepticism on how effective the rats are, not only among locals but also other mine action organizations because dogs have been so well accepted [as mine detectors],” he says. “But the rats have been operational in Mozambique for the last seven years or so and they have certainly proved themselves.”
Gilbert adds that rats have some advantages over dogs. For one, rats are easier to transport than dogs. And it takes much less time to familiarize rats with a new handler or a new environment.
Plus, they’re more efficient than metal detectors, which are sensitive to all sorts of metals, including those found in mineralized soil and trash. “The advantage of the rats is that they don’t look for metal, they look for explosives,” he says.
If you’re worried about rats exploding in midair—don’t be. Gilbert assures us that their sense of smell allows them to detect a land mine way before they step on one. And even if they do step on a mine, they’re far too light to activate it.
“They’ve got a bad reputation and they have been stigmatized for that. But our rats are doing good for mankind,” Gilbert says. “And they do it for peanuts.”