Rats sniffing out Cambodia's mine fields

TRACH, Cambodia - It's been a busy morning for Cletus, Meynard, Victoria and others of their furry band. Tiny noses and long whiskers twitching, they've scurried and sniffed their way across 775 square metres of fields to eliminate a scourge that has killed thousands of Cambodians: landmines.

See Full Article

Meet the Hero Rats: intelligent, surprisingly adorable creatures with some of the most sensitive noses in the animal kingdom. Sent from Africa, where they successfully cleared minefields in Mozambique and Angola, they began the same task in northwestern Cambodia early this month and have already scored tangible results.

Two hectares have been declared mine-free around this village where more than 15 people have been killed or wounded by the explosives, forcing some to abandon their homes and rice fields and seek jobs elsewhere.

One villager, Khun Mao, says the rats have been sniffing for suspected mines in a rice field he had been afraid to cultivate for years. He says that while it is too soon to say whether the rodents can remove every mine, "To me, these rats are wonderful."

"The villagers have started to get excited about farming their land again. You can see the light in their faces," says Paul McCarthy, Cambodia program manager for the Belgian non-profit organization APOPO, or Anti-Personnel Land Mines Detection Product in English.

On a recent morning, the African giant pouched rats were working two suspected, taped-off minefields. Each rodent wore a harness connected to a rope strung out in a straight line between two handlers standing about 5 metres apart and outside the danger zone. The rodents then darted from one handler to the other, constantly sniffing the ground and only taking time out to scrub their bodies with tiny front paws or to answer nature's call. The handlers moved a step or two down the field to repeat the process, and a second rat was later sent over the same terrain to double check.

Two-year-old Victoria proved particularly swift - "very active," one team member calls her. She stars in APOPO's "adopt-a-rat" fundraising drive.

At the second field, Merry and Meynard were completing three hours of effort as a midday sun beat down on the parched earth. The duo had earlier nosed in on an explosive, halting just above it and scratching the ground - the learned response when a rodent detects TNT inside a landmine. A deminer with a detector followed and the mine was dug up and detonated.

Unlike standard mine detectors, the super-sniffers pick up only TNT and not other metal objects. And unlike wage-earning humans, the rats work for peanuts - and their other favourite, bananas.

Theap Bunthourn, operations co-ordinator for the 34-member team, cited other advantages of using rats: They are cheaper to acquire and train than mine-sniffing dogs and easier to transport. Rats, averaging 1 kilogram, are also too light to detonate a pressure-activated mine. Dogs avoid that danger by staying a few feet away from the explosives they detect.

Each rat can clear an area of 200 square metres in 20 minutes, something a technician with a mine detector would take 1 to 4 days to complete. Their sense of smell is so keen that in Africa they are also used to detect tuberculosis in human sputum samples at a rate much faster than the standard laboratory method.

Unlike dogs, the rats don't get attached to their handlers and thus can be rotated among many, Theap Bunthourn says. But McCarthy, an ex-British Army demolitions expert, recalls watching the student rats "following their trainers like puppies, stopping when they stopped."

Critics say that rats may offer a lower level of guarantee that an area is mine-free than man-and-machine techniques, that the animals cannot search well in thick vegetation and can only work for relatively short periods in the heat.

"I would never discard any asset that could prove useful, but I can't envision hordes of rats wiping out minefields in Cambodia," says Greg Crowther, who heads the U.K.-based Mines Advisory Group in South and Southeast Asia. One of half a dozen demining outfits operating in Cambodia, MAG employs Belgian shepherds and a variety of mechanical devices.

"I don't think they can add a whole lot to what dogs can do. But if they can speed up the pace of demining, great. Let's wait and see," Crowther says. He adds that there is plenty of work to go around: It will take up to 15 more years to clear the country's explosives.

McCarthy notes that there was skepticism about using dogs to detect landmines decades ago, "and look at them now."

"As we accumulate more data, the more we break down the skepticism." McCarthy says APOPO, the only organization using rats, doesn't have the total solution for mine-clearing but just "one fantastic tool in the tool box."

The group was founded in 1997 by Belgian Bart Weetjens, who bred rats, hamsters and other rodents as a boy and developed the idea of using rats to find mines while at university.

Even Mark Shukuru was skeptical when he joined APOPO in 2001 at the group's headquarters in Tanzania. "At first I thought: 'Rats finding mines? It's impossible.' But they proved they could do it," he says, noting that in Mozambique they cleared more than 13,000 mines without a single injury, to humans or rats.

Shukuru shepherded the Tanzanian-born rats to Cambodia, one of the world's most heavily landmined countries, with up to 6 million mines or pieces of unexploded ordnance still left in the ground from decades of war. The mines at Trach were laid in the 1980s by Khmer Rouge guerrillas fighting the Vietnamese army.

Countrywide, about 67,000 people have been killed or injured since 1979, and with more than 25,000 amputees Cambodia has highest ratio of mine amputees per capita in the world, according to de-mining organizations. A mine accident occurs every 2 1/2 days on average.

Training the Cambodian rat contingent - eight males and six females - began at age 4 weeks by getting them accustomed to humans. This was followed by a rigorous, 9-month-long boot camp in Cambodia with APOPO, supported by the Cambodian Mine Action Center, one of a half-dozen demining outfits in the country.

The rats learned to associate a click with a food reward before being taught to respond to the scent of TNT. When they indicated TNT by scratching, a click was sounded and food followed. Eventually the click became unnecessary.

Before going into the field, the recruits are tested: One missed mine, and they don't graduate to Hero Rats, registered as the trademark HeroRATs.

Now, they are falling into an operational routine, usually working six days a week and being somewhat pampered when off-duty, sleeping indoors in roomy individual cages on wood shingles and kept healthy by regular exercise walking on a leash or on a running wheel. They are given multivitamins and weighed twice a week (a fat rat is a lethargic rat, one keeper says).

On weekends there's a special feast of apples, potatoes, watermelon and carrots. But what really drives their mine-sniffing are bananas and peanuts.

After the morning session, Victoria, Cletus and the others rested in portable cages near the mine fields while handlers offered them bananas, which they grabbed and greedily devoured. Grateful villagers gathered round the cages.

"It's not often you hear people say that they love rats," McCarthy says.

-----

AP writer Sopheng Cheang contributed to this report.



Advertisements

Latest Tech & Science News

  • Common genetic trait links human and doggy friendliness

    Tech & Science CBC News
    We may be more like our dogs than we know. Scientists studying the genetic basis for dog friendliness have found it comes from a portion of their genome that is similar to the area in the human genome that relates to sociability. Source
  • Man says he punched grizzly bear in the nose in B.C.

    Tech & Science CTV News
    QUALICUM BEACH, B.C. - A British Columbia man's beachcombing trip turned into a harrowing fight for survival as a grizzly bear flailed him around "like a puppet." Fifty-seven-year-old Randal Warnock says he had been walking on the beach on Brown Island on B.C. Source
  • 'Mystery' signal from space is solved; it's not aliens

    Tech & Science CTV News
    Astronomers have finally solved the mystery of peculiar signals coming from a nearby star, a story that sparked intense public speculation this week that perhaps, finally, alien life had been found. It hasn't. The signal, which has been formally named "Weird!" was interference from a distant satellite. Source
  • Possible melted fuel seen for first time at Fukushima plant

    Tech & Science CTV News
    TOKYO -- An underwater robot captured images of solidified lava-like rocks Friday inside a damaged reactor at Japan's crippled Fukushima nuclear plant, spotting for the first time what is believed to be nuclear fuel that melted six years ago. Source
  • Robot finds likely melted fuel heap inside Fukushima reactor

    Tech & Science CTV News
    TOKYO - An underwater robot has captured images of massive deposits believed to be melted nuclear fuel that are covering the floor of a damaged reactor at Japan's crippled Fukushima nuclear plant. Plant operator Tokyo Electric Power Co. Source
  • North Atlantic right whale to be examined on N.B. island

    Tech & Science CTV News
    MISCOU ISLAND, N.B. -- Marine mammal experts will examine another North Atlantic right whale today after it was found dead in the Gulf of St. Lawrence. The federal Fisheries Department says the necropsy is being conducted near the Miscou Island Lighthouse on the northern tip of Miscou Island, N.B. Source
  • Elephant seals have rhythm and they know how to use it

    Tech & Science CBC News
    New research published in the journal Current Biology finds that elephant seals identify one another by the rhythm in their calls, much the way humans can discern accents and vocal tone. Previously there was no recorded example of a non-human mammal that could remember and recognize a wide range of rhythms. Source
  • Moon dust collected by Neil Armstrong sold for $1.8 million

    Tech & Science CTV News
    NEW YORK -- A bag containing traces of moon dust sold for $1.8 million at an auction on Thursday following a galactic court battle. The collection bag, used by astronaut Neil Armstrong during the first manned mission to the moon in 1969, was sold at a Sotheby’s auction of items related to space voyages. Source
  • Moon dust collected by Neil Armstrong sold for US$1.8 million

    Tech & Science CTV News
    NEW YORK -- A bag containing traces of moon dust sold for $1.8 million at an auction on Thursday following a galactic court battle. The collection bag, used by astronaut Neil Armstrong during the first manned mission to the moon in 1969, was sold at a Sotheby’s auction of items related to space voyages. Source
  • China announces goal to dominate AI field by 2030

    Tech & Science CTV News
    BEIJING -- China’s government has announced a goal of becoming a global leader in artificial intelligence in just over a decade, putting political muscle behind growing investment by Chinese companies in developing self-driving cars and other advances. Source