I was reading through the latest addition of National Geographics, and there was a fabulous tidbit about heroRATS that go around and sniff out land mines, “some 60 million of which are scattered in 69 countries” (Mairson, Alan. National Geographics. Oct 2008, vol. 214, no. 4).
Why choose rats:
they are light, so they don’t detonate mines
found in many places, so the adapt to the surroundings
cheap to feed
easy to breed
have very sensitive noses