Pheromone

Charles Bonnet discovered insect trails but became famous for his hallucinations.

Dad was back. He played a little with the children, rubbed a few heads with his own, clawed at a wooden post, and then, standing erect with tail straight up, he backed towards a tree, sprayed, and left. The kids scampered over. They stood on their hind legs and carefully examined the spray—the family smell. […]