“The project has a number of roots. Elephants in Angola, which suffered decades of civil war, have been observed avoiding heavily-mined areas, suggesting their trunks were warning them to stay away.” (http://uk.reuters.com/article/2015/02/24/us-safrica-elephants-idUKKBN0LS0TF20150224)
One branch, on detecting TNT, wood quickly leaf the area.
Ecomical 