Highly sensitive smell organ...

A domestic cat's sense of smell is about fourteen times as strong as a human's. Cats have twice as many smell-sensitive cells in their noses as people do, which means they can smell things we are not even aware of. Cats also have a scent organ in the roof of their mouths called the vomeronasal, or Jacobson's, organ. When a cat wrinkles its muzzle, lowers its chin, and lets its tongue hang a bit, it is opening the passage to the vomeronasal. This is called gaping, "sneering", or "flehming". Gaping is the equivalent of the Flehmen response in other animals, such as dogs, horses and big cats.
Tags: Cats, wildlife