MEXICO: Huge pits dug in Tultepec, north of Mexico City, are providing greater understanding of the techniques humans used to hunt woolly mammoths 15,000 years ago. The two pits, each around 80 feet in diameter and 6 feet deep, contained 824 mammoth bones from 14 different animals. Researchers believe the pits were dug to trap confused mammoths, who were driven into them by hunters wielding torches and branches. The incapacitated beasts could then be more easily killed and butchered.