The "Stinky Face": Understanding the Flehmen Response in Cats

Have you ever seen your cat sniff something—a shoe, a blanket, or even your hand—and then freeze with their mouth half-open? It looks a bit like they’ve just smelled something offensive and are judging your life choices.

In the world of cat lovers, we often call this the "stinky face." However, in the world of science, it has a much fancier name: The Flehmen Response.

What is actually happening?

When a cat hangs their mouth open like that, they aren't actually "breathing" through their mouth. They are using a specialized sensory organ called the vomeronasal organ, or Jacobson’s organ.

This organ is located in the roof of the mouth, just behind the front teeth. By curling their upper lip and opening their mouth, cats allow scents (specifically pheromones) to reach this organ.

Why do they do it?

Think of the Flehmen response as a way for your cat to "taste-smell" the air. It provides them with much more detailed information than a regular sniff could. They use it to:

• Identify other animals: They can tell if a neighborhood cat has passed by.

• Check for pheromones: It helps them understand the social or reproductive status of other cats.

• Explore new scents: When they encounter a complex or unfamiliar smell, they use Jacobson’s organ to "analyze" the data.

Is it normal?

Absolutely! It’s a sign that your cat’s natural instincts are sharp. While it looks like a look of pure disgust, it’s actually a moment of intense concentration. They are essentially downloading data about their environment.

So, the next time your cat gives you the "stinky face," don't take it personally. They aren't saying you smell bad—they’re just doing some high-level chemistry!