We like diamonds because they are pretty, but the methods used to obtain them can be downright ugly. The people who have mined diamonds in Africa have endured myriad abuses in the century and a half since diamonds were first found there.
Modern-day smugglers get diamonds out with the help of pigeons. It's true, the birds can carry the weight of the little stones. This and other stories are told in Matthew Gavin Frank's book Flight of the Diamond Smugglers: A Tale of Pigeons, Obsession, and Greed Along Coastal South Africa.
The book takes detours from modern-day Africa to other times and places, detailing the rich history of human interaction with pigeons. The author visits.