The thirteenth volume of Chemical Signals in Vertebrates (CSiV) emanates from the first joint meeting of CSiV and the International Society of Chemical Ecology (ISCE), which was held at the University of Illinois Urbana-Champaign in June 2014. Chemicals involved in communication in both mammals and insects are by and large secondary metabolites-that is, they are generally not molecules involved in the primary physiological processes of life, such as respiration, digestion, excretion, and in the case of green plants, photosynthesis. .