Tristram Wyatt's introductory text on pheromones and animal behavior is clearly written, most terms are defined with pointers to their origins, and terms are consistently used. His presentation is comprehensive in that its follows a list of sexual, alarm, aggregation, recruitment, scent, primer, and orientation pheromones, devoting a chapter to each. He includes summary tables, helpful illustrations, examples from many species, and discussions of the literature to date. He explains the chemistry of chemical signals, the anatomy of production and uptake, and observed biological consequences for reproduction and social organization. Following its list of pheromones, his book closes with a chapter on the preliminary use of pheromones and a chapter on the inconclusive data as to the possibility that humans may use sexual pheromones. Darwinian biology underlies references to theory, but Darwinian evolutionary theory itself is not formally explicated. He reports the familiar just-so stories that Darwinians speculate with, but mostly just reviews the various Darwinian hypotheses on the relation of reproduction to speciation and hedges when data do not support the theory and when the theory does not explain the data. Anyone who wants an overview and update on the technical literature will greatly benefit from this nicely written, professional book.