A recent study showed that, similar to dogs, humans can accurately trace the path of a scent trail using a zigzagging pattern. After a few days' practice the subjects became even better and faster at it. There already was evidence that babies can use their mother's odour to orientate themselves, according to Peter Brennan of the University of Bristol; however, “this is the first time that adult humans have been shown to follow a scent trail” (BBC News Online, 18 December 2006).

Humans were better at tracing the scent when they could smell through both of their nostrils, suggesting that nostrils were used in tandem to sense which of the two was closest to the track. The nostrils' owner could then adjust their search path accordingly. Neil Vickers of the University of Utah says: “This is the first evidence ... that there's some spatial separation between the air that's coming into the two nostrils and that could potentially give [humans] some information about which way to go” (ScientificAmerican.com, 18 December 2006).

Some other animals also smell in stereo. “It now seems that there's a common mechanism of scent localization from insects to humans,” says Matthias Laska, a sensory physicist at Linköping University in Sweden (NewScientist.com, 17 December 2006).

The question remains how much we make use of our scent tracking ability in daily life. Brennan says: “...it would be interesting to study the extent to which blind people make use of their sense of smell for finding their way around their environment” (BBC News Online).

For Jay Gottfried of Northwestern University in Chicago, the study highlights “that the human sense of smell is a lot better than many people think it is”, although he adds: “I don't think this means people will ever take the dog's place on a fox hunt” (Chicagotribune.com, 18 December 2006).