Smell
From Conservapedia
The Sense of Smell is that sense which is controlled by the nose, also known as the Olfactory. It is used to detect and recognize substances at a distance.
Much of the animal kingdom has a keener sense of smell than humans, and is an important part of survival. Smell is used to help determine which foods are edible, to avoid predators or other objects of danger, and as an attractor for reproduction especially through pheromones.
Much of taste is also determined by smell.
Sources
The New American Desk Encyclopedia, Penguin Group, 1989