|Smell is an extremely important sense in cats, in some cases more than sight. Cats have scent glands on multiple places on their body including their faces and feet. On their face, the glands are located around the eyes, below the ears, and on the chin. By rubbing their face on various objects, such as legs and furniture, they are leaving their scent. Other cats passing the object will often stop and sniff, maybe even rubbing their faces on the object to leave their scent as well.
Scent marks contain molecules called pheromones. Different glands secrete different pheromones which affect a number of behaviors, including reproduction and establishing territory.
The pheromones that come from the glands on the face generally have a calming effect on cats. A product called 'Feliway' is now on the market that contains these facial pheromones. When applied to vertical surfaces, it can decrease a cat's tendency to spray (mark the area with his urine).