Humans have looked to a variety of animals to help detect explosives.

Research in South Africa showing that elephants can identify explosives by smell follows a long tradition of such experiments.

Dogs are commonly used to sniff out explosives, contraband and other illegal items. A group called APOPO had such good results with trained rats that it has deployed them to detect mines in Angola and Mozambique and uses them in Tanzania to screen people for tuberculosis by evaluating sputum samples. In Croatia, where mines were left from the 1990s Balkan wars, researchers noted that bees gathered at pots containing a sugar solution mixed with TNT, though the insects have not been used for de-mining.

The U.S. military is a major funder of the elephant research. Stephen Lee, head scientist at the U.S. Army Research Office, downplayed any parallel between the research and the exploits of Hannibal, the general of ancient Carthage who crossed the Alps with elephants.

"There's never an intention that we're going to use elephants on the battlefield," Lee said. The goal, he said, is to learn how an elephant smells and incorporate that knowledge into electronic sensors.

Some animals have turned mine fields into "de facto wildlife preserves," mostly avoiding mines in areas where people fear to tread, commentator Michael Moore wrote in January in his blog, "Landmines in Africa."

He cited leopards on the border between Iran and Iraq, which fought in the 1980s; penguins in the Falkland Islands, where Britain fought Argentina in 1982; and wolves in the Golan Heights between Israel and Syria.

"Land mines do not protect habitats, merely demonstrate the importance of guaranteeing safe and secure habitats for all species," Moore wrote.