Have you ever seen your cat make a funny slack jawed face? They may look like they are concentrating with eyes wide and whiskers puffed out. I’ve had clients say their cat was “mad” when they made this face or perhaps not very smart. Why does your cat do this?
The scientific name for the slack-jawed face is the “flehmen response.” Cats have a Jacobson’s Organ in their mouths next to the nasal passage. When smelling the pheromones of another cat, they hold the odor in their mouths up to the Jacobson’s Organ to get a whiff. This results in the flehmen response face. They are not angry or dull witted, they are just getting a more thorough understanding of another cat. It’s kind of like when someone pours a fine wine for you. You want to twirl the glass and waft the aroma to really experience it.
Think about when your cat has made this face. Did you just come back from visiting a friend with cats? Volunteering at the shelter? Cat sitting for a neighbor? These are all ways you can bring home the pheromones of another cat, triggering the flehmen response in your cat.
There’s no need to worry. Your cat is normal and expressing a function that we’ll only ever understand conceptually. Give them a good pat and praise their talent!