The elaboration of analytical techniques in recent years has made it possible to characterize natural products in microquantities, leading to an enormous increase of interest in and kfiowledge about "infochemicals", "semiochemicals", "pheromones", "alMochemics", "ecomones" and other kinds of compounds governing interactions among organisms. One can not only identify new chemicals but also routinely determine subtle variations in naturally occurring chemicals, and how they change spatially and temporally. In particular, the integration of chemical and biological approaches has created a considerable body of information which at last allows to begin to appreciate the biological significance of natural products and their roles in complex interactions. With the demonstration of the overwhelming importance of chemical communication in nature, we have witnessed the growth of a new discipline: chemical ecology. There is difference in opinion on where emphasis lies in this multidisciplinary field, and epithets such as "ecological chemistry", "ecological biochemistry", and "molecular ecology" have been used in a seemingly synonymous way. As chemical ecology grows some misunderstanding and questioning regarding its core philosophy remains within both the scientific community and the public at large. But fortunately, neither semantic problems, nor differences in opinion have caused interest in the subject to diminish. In fact, the subject is attracting more and more students and is receiving increasing attention.