Benjamin Long writes to note a study, by a team of neuroscientists and engineers, that demonstrated that humans can follow a scent trail — an ability that most had assumed only animals possessed. Furthermore, the study demonstrated for the first time that humans make use of differential information from the two nostrils. The researchers blindfolded college students who crawled through grass to sniff out a chocolate-scented trail. Here is the abstract of the paper in Nature Neuroscience. From the article: "The humans, however, still sniffed much more slowly than dogs, which may partially account for canines' greater efficiency at scent tracking. [A commentator] says that despite their relatively sluggish speed, the fact that subjects improved with training is noteworthy. 'I think that shows the effect of our distinctively different behavior in actually using this sense,' he says. 'The dog [has] been doing this its whole life, and humans [were] just asked to plunge in the first time they've ever done it.'"