A pilot project in Colombia is training the highly intelligent rat to locate landmines, with the animal's light body weight allowing it to navigate safely as its keen sense of smell detects the explosives to help restore lands and save hundreds of human lives each year.

http://www.trust.org/alertnet/news/rats-help-colombia-sniff-out-deadly-landmines/
http://tribune.com.pk/story/296855/rats-help-colombia-sniff-out-deadly-landmines/