The importance of chemical communication is illustrated in this study with examples from a diverse range of animals including humans, marine copepods, Drosophila, Caenorhabditis elegans, moths, snakes, goldfish, elephants and mice. For students of ecology, evolution and behavior, Tristram Wyatt provides an introduction to the rapid progress in the understanding of olfaction at the molecular and neurological level. In addition, he offers chemists, molecular biologists and neurobiologists insights into the ecological, evolutionary and behavioral context of olfactory communication.