These rats, nicknamed "HeroRATS", have been deployed in Mozambique and Cambodia. APOPO credits the rats with clearing more than 100,000 mines. Rats have the Demining or mine clearance is the process of removing land mines from an area. In military operations, the object is to rapidly clear a path through a minefield, and this is often done with devices such as mine plows and blast waves. By contrast, the goal of humanitarian demining is to remove all of the landmines to a given depth and make the land safe for human use. Specially trained dogs are als The conventional method of landmine detection was developed in World War II and has changed little since then. It involves a metal detector, prodding instrument and tripwire feeler. Deminers clear an area of vegetation and then divide it into lanes. A deminer advances along a lane, swinging a metal detector close to the ground. When metal is detected, the… Preferred breeds for MDDs are the German Shepherd and Belgian Malinois, although some Labrador Retrievers and Beagles are used. They cost about $10,000 each to train. This cost includes 8–10 weeks of initial training. Another 8–10 weeks is needed in the country where the dog is deployed to accustom the dog to its handler, the soil and climate, and the type of explosives. MDDs were first deployed in WWII. They have been extensively used in Afghanistan, which still has one of the largest programs. Over 900 are used in 24 countries. Their preferred role is for verifying that an area is cleared and narrowing down the region to be searched. They are also used in Remote Explosive Scent Tracing (REST). This involves collecting air samples from stretches of land about 100 metres (300 ft) long and having dogs or rats sniff them to determine whether the area needs clearing.