A pheromone is a chemical signal that triggers a natural response in another member of the same species. There are alarm pheromones, food trail pheromones, sex pheromones, and many others that affect behaviour or physiology. Their use among insects has been particularly well documented. In addition, some vertebrates and plants communicate by using pheromones. This book examines trail pheromones and sex pheromones in termites and their potential use in pest management and insect repellents. Also discussed is splendipherin, the aquatic male sex pheromone of the tree frog as well as the study of "human pheromones".