Mozambique has just been declared free of landmines! It was done with the help of specially trained giant rats.
Flickr gallery of pictures of the rats and their handlers. (via an AMA on Reddit with
two people from one of the organizations involved in clearing the landmines.)
edit: A reply from the AMA asking about what species of rat they are: "Thanks for your question! We train Gambian Pouched Rats which are a different species to the ones that people tend to keep as pets which are normally the Norwegian variety. Our rats are much bigger, nearly twice the size, and are native to the parts of Africa that we work in. They are resistant to disease, easy to train, have an exceptional sense of smell, and are a bit like dogs really. Very friendly, charismatic, curious, affectionate, they are great creatures to work with!"