“That’s my blood, not the deer’s,” said Eden Kloetzli, a senior at Washington College, in Maryland, as she gazed at the red liquid staining her palm. She and about a dozen other students were busy slicing and dicing four deer carcasses laid outside the school’s new archaeology laboratory. Making the task harder, the novice butchers were using tools that they had knapped themselves out of obsidian, basalt, and flint.