Arms flailing and menace in her eyes, the woman charges me from behind a pile of cages. I heard her husband say something about giving her a cuchillo—a knife. "No photos!" she yells in Spanish. "Don't take photos! Get out of here!" I back away slowly. We are in Xochimilco, a lively, outdoor market in Mexico City, where this woman is running a puesto, or stand for selling animals. She has stacks of animals in cages all around her, like walls of living creatures. In her cages are yellow-cheeked Amazons and orange-fronted parakeets—native Mexican parrots, caught in the wild.