Cats open their mouths when they smell something as part of a behavior called the Flehmen response. This behavior allows them to draw scent molecules into a specialized organ on the roof of their mouth called the vomeronasal organ or Jacobson's organ. By opening their mouths and slightly grimacing, cats enable chemical cues, especially pheromones, to reach this organ, helping them better analyze the scent. This is a way for cats to "smell in high definition," gathering detailed information about their environment, other cats, or potential mates beyond what their noses alone can detect.
Details on the Flehmen Response
- The Flehmen response opens two small ducts behind the cat's front teeth, allowing scents to travel to the vomeronasal organ.
- This organ detects pheromones and other chemical signals that are important for communication, mating, and territorial behavior.
- The response looks like a grimace or sneer with the cat's mouth partially open and upper lip curled back.
- It is voluntary and common in many mammals, not just cats, and is more often triggered by strong or unusual smells.
Purpose and Triggers
- Enables cats to detect chemical messages other cats leave, such as territorial markers or readiness to mate.
- Helps kittens absorb pheromones from their mother, providing comfort.
- Commonly triggered by new, strong, or interesting scents like urine, sweat, or pheromones from other animals.
In sum, cats open their mouths when smelling as a specialized sensory adaptation to analyze complex chemical signals crucial for social communication and environmental awareness. This behavior is normal and an important aspect of how cats interpret their world.