Louise Hecker, Graduate Student, Department of Cell and Developmental Biology, University of Michigan Medical School

One of the amazing ways in which animals communicate is by pheromones. In the red-backed salamander (Plethodon cinereus), these chemicals are released from skin glands in the tail and play a role in species recognition, territory marking and mating behavior. In this photograph, cells synthesize pheromones (turquoise) and pack the aromatic chemicals into small oil droplets. By studying pheromonal communication in other animal species, we can gain a better understanding of how humans might unwittingly use this evolutionarily ancient form of communication.