CANADA: When archaeologists in the southern Yukon recovered a 6,000-year-old atlatl dart—a deadly projectile used by First Nations peoples—from melting alpine ice, they noticed it was coated with a mysterious orangish substance. The researchers initially suspected it was red ochre, but further examination revealed that it was actually castoreum, a secretion beavers use to mark their territory. This is the first known archaeological evidence of the substance’s use. It might have been applied to the dart as an adhesive, a preservative, or a colorant.