Camilla Jessen
Did you know this?
That funny grimace your cat pulls — mouth slightly open, lip curled, teeth showing — isn’t disgust or surprise. It’s actually a special tool for detecting scents.
The flehmen reaction explained
Cats sometimes pause mid-sniff and make a peculiar face that can look like a comical mix of shock and disgust.
But this is not about a bad smell.
It’s called the flehmen reaction, a biological response that helps cats gather extra information about the world around them.
Pheromones are the key
The strange expression happens when cats pick up pheromones — chemical signals left behind by other cats and animals.
These scents carry information about territory, mating and identity that a regular sniff alone can’t fully decode.
How cats “taste” smells
When a cat opens its mouth during the flehmen reaction, it draws pheromone-rich air up to the roof of the mouth.
There, tiny channels lead to a special sensory organ called Jacobson’s organ, located at the base of the nasal cavity.
This organ processes pheromones and sends signals to the brain, offering insights far beyond ordinary smell.
Why male cats do it more
While all cats are capable of the flehmen reaction, males are particularly prone to it.
That’s because sex pheromones — especially from females in heat — strongly trigger the response.
Not just cats
Cats aren’t the only animals with this unique “scent face.”
According to Illustreret Videnskab, horses, goats and even big cats like lions and tigers also use the flehmen response to analyze chemical cues in their environments.
A window into their world
So next time your cat freezes with its lip curled and teeth showing, it’s not being dramatic.
It’s using a finely tuned biological tool to detect hidden messages in the air — and giving you a glimpse into the mysterious way cats experience the world.
This article is made and published by Camilla Jessen, which may have used AI in the preparation
