Several of Weetjens' family members had worked in Africa

Several of Weetjens' family members had worked in Africa, and Weetjens harbored a commitment to the continent. In the spring of 1995, he was analyzing the world's land mine epidemic -- a cause made vogue at the time by Britain's Princess Diana -- when he came across research that spoke to his childhood proclivity.

Scientists were studying the use of gerbils in land mine detection, but they were using a system involving brain electrodes that Weetjens found unsustainable. He wanted a locally based solution that might empower communities.

"Yes, rats can do that," he thought. "I knew I was right, even if it was very hard to defend."

See APOPO videos of the rodents at work

It's difficult to quantify the scourge of land mines in Africa. Experts are reluctant to give statistics, but it's safe to say there are single countries hosting millions of them.

The International Campaign to Ban Landmines says land mines and related devices were responsible for 73,576 casualties worldwide from 1999 to 2009. Campaign data from 2007 say there were 5,426 recorded casualties, with almost a fifth of them in 24 African countries.

Death and injury, however, are only two ramifications of the buried terrors, said land mine expert Havard Bach, formerly of the Geneva International Center for Humanitarian Demining.