http://www.senseofsmell.org/feature/smell101/lesson1/01.php
Whether for finding food, avoiding predators or choosing a mate, the sense of smell is critical for the existence of almost all creatures. We humans, able to distinguish over 10,000 different odor molecules, utilize our sense of smell for a multitude of activities from enjoying the aroma of freshly brewed coffee to deciding whom not to sit next to on the bus.
