Happy #NationalCatDay! Wondering what this face is about? Cats (along with goats, tigers, horses, and other animals) are known to exhibit the “flehmen” response, a reaction in which animals inhale and expose their upper teeth to identify certain smells (especially pheromones). Here’s how it works: the response opens the nasopalatine canals—located on the roof of the mouth—which lead to the vomeronasal organ, a special patch of sensory cells which help detect airborne odor particles. Here’s an album of cats (and a few other animals too...we couldn’t help it) making the odd face that results. #dotheflehmen 🐱👃 . . . . . . . . #smell #sense #senses #animals #animalsofinstagram #catsofinstagram #catday #flehmen #flehmenresponse #smell #cats #omgcats #science #biology #life #face #Instacat #Instacats #Meow #Cutecat #Instapet #Catoftheday #Kittylove #Instakitty #Catlover #cute