How do demining rats work?

3-year-old Samo sniffs around with his nose as he moves quickly across a green field. He is tethered to a rope and runs through a minefield separated by a cordon. Suddenly, he stopped and sniffed around alertly. Then he stretched out his front paws and pawed the ground, signaling his trainer, Shrima Wendelin Emmanuel, with a gesture that he had found a mine. Emanuel was standing a short distance away in a safe place. Emanuel excitedly shouted, "Good job, Samo!" At that moment, Samo came bounding toward him to claim his prize. The prize was a banana. Samo was not a doll soldier, but a larger Gambian kangaroo.

Global demining methods vary

It is extremely difficult to clear the land of landmines. It is estimated that about 100 million mines have been planted around the world, and efforts to remove them have led to a number of bizarre and innovative approaches. A Cambodian newspaper has proposed taking British cattle suffering from mad cow disease and letting them walk around the countryside to detonate the nearly 11 million mines planted underground in the country.

More traditional methods of demining all fall short. Armored mine-clearing vehicles can work only on flat terrain; metal detectors are highly inefficient because they react to all non-lethal metals in the ground; and dogs can sniff out explosives in mined areas, but they are easily distracted and often die from mine strikes because they don't follow the rules.

So when researchers at Tanzania's Sokoine University of Agriculture began training Gambian kangaroos for mine clearance, Mozambicans were more than willing to give it a try. Tanzanian Gadi Mikumbo, who supervises this training and the trainers, said, "Gambian kangaroos are very smart and they love to learn new things. You can train them to learn everything you want them to do."

The Gambian kangaroo training program, which is run by an organization called Apopo and funded by the Belgian government, has proved so effective that a group of mine-sniffing rats will enter Angola at the end of 2008 to carry out mine-clearing duties.