ASK THE EXPERT: What’s up with cats making a “stink face” during my Zoo visit?
Posted on Thursday, July 6th, 2023
Not to worry! This is a completely normal thing for cats to do and there’s nothing “stinky” about it!
Amur tiger Anya displays the flehmen response in this summer 2021 photo.
Many mammals (such as cats, horses and goats) and reptiles (like snakes and lizards) are olfactory animals, meaning their sense of smell is extremely important. Let’s focus on the Zoo’s big cats.
Did you know cats have an extra special sense of smell thanks to an auxiliary organ called the vomeronasal organ (VNO)? "This special organ can be found at the base of the nasal cavity and it acts as a sixth sense. When a cat utilizes their VNO, it sends signals directly to their brain about what they’re smelling. It’s high-tech smell-o-vision!" says Jen DeGroot, Associate Animal Curator.
The animal world calls this behavior the flehmen response. “Flehmen” comes from the German language and means to curl the upper lip. When a cat uses their VNO, you might see one or several things happen: curled upper lip, tongue stuck out, mouth opened, teeth exposed.
Amur tiger Anya displays the flehmen response in this summer 2023 photo.
Jen says these are all actions that allow a cat to use their special organ to diagnose a smell. At the Zoo, there are so many smells! From a breeze bringing pollen into a new area to tigers swapping yards at Rosebrough Tiger Passage, there are ample opportunities for the Zoo’s cats to show their flehmen response.
So that “stink face” you might see is Anya the tiger analyzing a particular smell! Keep an eye out on the Zoo’s big cats during your next visit and see if you can find any of these smelling behaviors.
Bonus Fact: According to Jen, Animal Care staff pay attention to the flehmen response during breeding introductions with animals like tigers. Both the male and female smell each other’s hormones during estrus, which is a period when the female is ready to accept a male and to mate. It’s one of the ways Zoo staff determine when the cats are ready to be introduced for breeding.
