Have you ever noticed your cat staring off into space, perhaps in a way that’s trance-like, while curling back her upper lip? It can be a funny sight if you don’t understand what’s happening (or even if you do)! The act is called the flehmen response and it allows your cat to smell through her mouth! Cool, right?
“Flehem” is a German word that means to bare upper teeth or to curl the upper lip. Cats who are flehming may look as if they’re disgusted due to the expression we perceive as a grimace, but the opposite is actually true. Cats will shrink away from smells they find unpleasant (think of how your cat reacts to citrus, for instance), but a cat who is flehming is instead captivated and focused. The flehming response means your cat is smelling something she finds very interesting and is using her whole toolbox of skills to get more information.
You see, your cat has an organ on the roof of her mouth, located right behind her front teeth. It’s called the vemeronasal organ or the Jacobson’s organ. The organ is lined with receptors that act to amplify your cat’s sense of smell. The organ sends signals to your cat’s brain and gives her a heightened awareness of her surroundings. In a way, it allows her to “taste” the air.
While all cats may be seen flehming from time to time, male cats are more prone to it than females. That’s because male cats often use it as a way to find a mate. The flehming response is so strong that it actually helps male cats determine whether a certain female cat is in heat or fertile simply by smelling her pheromones or urine.
Is the flehming response a tool your cat takes advantage of? Start watching for it! Cats use all of their senses to explore and understand their world, and the flehming response helps keep a paw on the pulse of their surroundings.