More than 100 million land mines have been planted just beneath the soil in 90 countries. Land mines are responsible for killing or maiming about 40 to 55 people every day, according to estimates provided by the Red Cross.
There are approximately 500 mine-sniffing dogs deployed worldwide to help detect deadly unexploded land mines, so that they can be removed safely. The dogs were introduced a decade ago, because they have fewer false positives than metal detectors, and they've been widely accepted by groups working to remove land mines. But a Belgian-based group, APOPO, has begun employing a new mine hunter that has proven to be much better suited to the work.
Bart Weetjens, the founder of APOPO, has been running a lab in Tanzania for the past seven years training Gambian giant pouched rats to sniff out land mines. Weetjens and his group have trained the rats using classic conditioning techniques such as Pavlov used to train his dogs. First, a clicking sound is associated with a food reward. Then trainers watch to see when the rat smells the explosive, then they use the clicker to associate that behavior with the food reward the click gets them. Once the rat knows that the mine-detecting behavior will result in food, it will repeat the behavior. Weetjens estimates that a rat's training takes approximately two to four months―half the time it takes to train a dog―and the teams of rats are less expensive to operate in the field.
Weetjens says that the rats are much more efficient at sniffing out land mines, because they are more focused. Dogs get so excited when they find a mine that they get distracted, whereas, the rats are fixated on getting as many food rewards as they can, so they work better in densely mined fields. Also, they weigh much less than dogs, so they are less likely to set off the mines. The giant rats usually weigh only about 3 - 4 pounds, and can reach a total length of 30 inches or more, including their tail. They can be equipped with wireless cameras and sent into collapsed buildings, and they are less susceptible to tropical diseases. But dogs can cover more ground more quickly, and they are more culturally acceptable in some countries.
Still, Weetjens says, his 'hero rats' are a much better option for detecting and disarming land mines. The African giant pouched rat was specifically chosen because of its unique abilities. The pouched rat is not nervous and has an extremely keen sense of smell. Its behavior is very stable and it interacts well with humans. But the main quality that makes the giant pouched rat the perfect candidate for sniffing out mines is that they don't eat their food immediately. A giant pouched rat packs food in the pouches of its mouth until they return to its nest, where the food is buried and stored for later. So when they are sniffing out land mines and they get a reward, the rats don't stop to eat it―they keep on sniffing.
Weetjens hopes that people can get past the centuries-old misconceptions about rats, to realize the great benefit his rat teams can offer to the world. "These rats, they're just nice creatures," he says. "Of course, they do destroy crops and do transmit diseases. But if you treat them well and give them the proper housing and the proper care, they are actually very organized, neat animals. They're very kind, and they have very complex social structures."
If you'd like to sponsor a giant mine-sniffing rat, visit the Hero Rat website to select your rat and make a donation of five Euros. The rats currently available for sponsorship on the site include a newly born rat, one beginning training, a fully active HeroRat, and a special two for one deal named Posh and Becks. You'll get pictures of your rat, as well as regular updates from trainers on your rat's individual progress, either in training or out in the field sniffing mines. And you'll get an official HeroRat adoption certificate to hang on your wall.