Chemical ecology is at the forefront of biogenetic exploration since it links chemistry and biology - the two primary disciplines underlying agriculture and medicine. Chemical ecology can be defined as the study of chemical interactions between organisms and their environment, which includes other organisms. Organisms use chemicals to lure their mates, associate with symbionts, deter enemies, and fend off pathogens. Chemical ecology is a multifaceted discipline, intent on deciphering both the chemical structure and the information content of the mediating molecules. While the messenger compounds can be grouped into a mere handful of chemical classes, structural modifications to each biosynthetic theme have led to hundreds of thousands of individual compounds in nature. Chemical ecology, thus, is a discipline in which discovery is still very much in order, for the interactions themselves remain in large measure to be uncovered. Chemical ecology has achieved a higher level of world recognition in recent years because of advances in both chemistry and biology. In chemistry, extraordinary technical innovations have taken place for separating complex mixtures into their individual components, as well as for quantification and chemically characterizing designated compounds. There has been a vast increase in the sensitivity of the techniques that makes it possible to define signals that take place with a small number of molecules. In biology, conceptual advances in behavioral biology, particularly sociobiology, have helped to put new slants on inquiries into such social phenomena as mate attraction, sexual selection, parentalinvestment, caste determination, and colony organization, all frequently mediated by chemicals.