Sniffing danger

How a dog uses its nose

source: Mark Schrope
New Scientist August 26 2000 p16

Researcher, Gary Settles, from Penn State University, has studied how dogs sniff. He found that they breathe in cool air, exhaling it as warm air, and this exhaled air is diverted away from the object they are sniffing. Dogs exhale through the side slits of their noses, so the exhaled air can be directed away from what the dog is sniffing. The scent can thus be separated from the air exhaled by the dog, while new air is pulls across the object, which makes odour molecules rise in the air. Dogs alter the shapes of their noses on inhaling, so as to be able to inhale large amounts of air. Settles carred out his research following a request by the military. This finding could help with developing mechanical dogs to locate landmines.