Pheromones in nature are chemical messages that act within a species. It was Karlson and Lüscher who coined the term “pheromone” to cover the wide range of substances secreted to the outside world by individual organisms and received by other individuals of the same species. Pheromones are used widely by insects. The analogy between this mode of communication within an insect society and communication within the body by means of hormones, led to these substances also being referred to as “social hormones.” (Wigglesworth VB (1970) Insect Hormones. pp. 134–pp. 141. W.H. Freeman and Company.) These chemical messages have diverse biological effects and differ widely in their modes of action. In practice, the term “pheromone” proves useful in describing behaviors such as trail formation, defensive secretions, and social coherence.