The Pentagon has been looking for technologies to use people's scents to detect, track, and identify them from a distance. The most start-of-the-art technology so far has only been able to distinguish between two different people and needs armpit scent—but now the Army is seeking proposals for a more sophisticated detection system. It is looking for a product that could “uniquely identify an individual based on scent,” at a geographical distance or after several hours or even days.