Dr Tristram Wyatt is a senior researcher at the Department of Zoology, University of Oxford and an emeritus fellow of Kellogg College, Oxford. He is interested in how pheromones evolve throughout the animal kingdom, at both molecular and behavioral levels. The second edition of his book Pheromones and Animal Behavior will be published by Cambridge University Press in late 2013. In his TED talk "Success of the smelliest? Do humans have pheromones?", Dr Wyatt will touch upon the sense of smell. Moths, goldfish, snakes and fruit flies all react to pheromones (chemicals for communication). Get a sniff of the science with Dr Tristram Wyatt as he talks through how the behaviour of the animal kingdom is changed by these invisible molecules, why humans are smelly and why sex may be the reason behind it all. Charles Darwin included chemical signals alongside visual and sound signals as results of sexual selection, describing how male crocodiles and goats get smelly in the breeding season. He suggested that elaborate odour glands in male mammals evolved because the most odoriferous males were the most successful in winning the females. The success of the smelliest! What about humans? Is smelly sexy? Emperor Napoleon thought so. Do we have pheromones? The circumstantial evidence is good: we are mammals and almost all other mammals use pheromones; we have smells that change with puberty and arm pits seem to be designed as perfect pheromone factories. Sadly, despite what's on the Internet, there is no evidence yet of a human pheromone to make you irresistible. There is a story to tell though.