A heroic rat named Magawa is retiring from sniffing out dozens of land mines in Cambodia for the last five years. NPR reports: Magawa is a Tanzanian-born African giant pouched rat who was trained by APOPO to sniff out explosives. With careful training, he and his rat colleagues learn to identify land mines and alert their human handlers, so the mines can be safely removed. Even among his skilled cohorts working in Cambodia, Magawa is a standout sniffer: In four years he has helped to clear more than 2.4 million square feet of land. In the process, he has found 71 land mines and 38 items of unexploded ordnance. Last year, Magawa received one of Britain’s highest animal honors.
Magawa is part of a cohort of rats bred by APOPO for this purpose. He was born in Tanzania in 2014, socialized and moved to Siem Reap, Cambodia, in 2016 to begin his bomb-sniffing career. APOPO uses positive reinforcement methods that give the rats food rewards for accomplishing tasks such as finding a target or walking across a surface. Then they’re trained in scent discrimination: choosing explosive smells over something else to get a food reward. Though they have terrible eyesight, the rats are ideal for such work, with their extraordinary sense of smell and their size — they are too light to trigger the mines. When they detect a mine, they lightly scratch atop it, signaling to their handler what they’ve found. Their reward: a banana. [T]he rats hone their skills in a training field and are only cleared to begin work once they have perfect accuracy over an 8,600-square-foot area with various stages of complexity.