Humans can track scents?
If the results are surprising, that might be because no one ever tried putting a bunch of college undergraduates in a field wearing blindfolds and sound-muffling headphones, then having them crawl in the grass after a scent.
When researchers at the University of California, Berkeley did try that, they found that most of the students could follow a 30-foot trail of chocolate perfume; they even changed direction precisely where the invisible path took a turn. What's more, the subjects were able to smell in stereo: When researchers blocked their ability to smell independently with each nostril, the students' scent-tracking accuracy dropped off drastically.
OK, this is interesting, but the article doesn't say how strong the scent was, or how humans performed compared to bloodhounds or other animals with a keen sense of smell.