In Cambodia, Rats Are Being Trained To Sniff Out Land Mines And Save Lives : Parallels : NPR
Each rat is responsible for clearing a 200-square-meter (239-square-yard) patch of land. Their Cambodian supervisor, Hulsok Heng, says they're good at it.

"They are very good," he says. "You see this 200 square meters? They clear in only 30 minutes or 35 minutes. If you compare that to a deminer, maybe two days or three days. The deminer will pick up all the fragmentation, the metal in the ground, but the rat picks up only the smell of TNT. Not fragmentation or metal or a nail or a piece of crap in the ground."