The Cat's Olfaction
Odors play an important role in the behavior of cats. This is illustrated by the sheer size of the olfactory epithelium and the large number of scent receptors compared to humans.
Cats also have the sniff mechanism which aids in maximizing scenting ability. The sniff is actually a disruption of normal breathing and consists of a series of very rapid, short inhalations and exhalations. Sniffing forces air into a bony structure that traps the inhaled air. Instead of being further inhaled into the lungs, the air rests in this space to allow scent molecules to interact with scent receptors in the nose.
The cat also has an additional olfactory organ called the vomeronasal organ, also commonly referred to as the Jacobson's organ. This organ, found in the roof of the mouth, contains receptor cells that connect to the region of the brain associated with sexual, feeding, and social behaviors. It's believed that the vomeronasal organ is involved in courtship and sexual behavior, as well as the ability of a cat to recognize other cats and people.