Horizontal rays of light pierced the canopy, giving the tops of leaves a ruddy shine. I was alone in the forest, and I wanted to return home before dark. But I also wanted to see where Mitchell, an enigmatic adolescent chimpanzee, made his nest for the night. I live in the middle of the Ugandan forest, at Ngogo Research Camp, which is within the territory of the Ngogo chimpanzee community. I’m here to study the transition to adulthood in male chimpanzees.