According to neurobiologist John McGann of Rutgers University in the US, poor human olfaction is a 19th century myth. The idea that humans have a relatively poor sense of smell, he argues, did not come from empirical studies of human olfaction but from a 19th century anatomist’s idea that human free will required a reduction in the brain’s olfactory bulb. In reality, our olfactory bulbs are quite large and have similar numbers of neurons to those of other mammals. In fact we are able to track odour trails, and are even more sensitive than rodents and dogs to some odours.