I was sitting in the playroom at the cats-only boarding facility with a pair of cats from the same family. You may remember them — the annoying younger cat who kept patting his brother’s rump for attention?
I had my legs stretched straight out, and the two cats were walking back and forth sniffing me. After sniffing a particular spot on my leg, the younger brother looked up at me and made a weird face. His mouth was hanging open, his nose twitched, and his lip curled up.
This reaction is known as flehming.
Cats have a vomeronasal organ (also known as the Jacobson’s organ) in the roof of the mouth — this organ traps scent molecules and sends special signals to the brain. When you see your cat making that odd face with his mouth hanging open, he’s having a flehmen reaction. He’s drawing the scented air and transferring it to the vomeronasal organ. The facial contortions actually help open the ducts that connect the vomeronasal organ to the nasal cavity.
Weird, huh? For a cat, this reaction is perfectly normal.
You may see your cat flehming after any number of scents. It is most often seen when a cat smells the scent of urine or an animal in heat. I’m not surprised that the cat in the playroom was having a flehmen reaction to the smell of my work scrubs. I get all sorts of interesting smells on my scrubs: used litter pan smells, food smells, and the scent of other cats… not to mention the smell of dogs that comes with me.
Cats have far more sensitive sniffers than humans do. Smells that we can’t detect are loud and clear to a feline nose! So you don’t have to feel dirty or stinky if your cat gives a flehmen reaction after sniffing you.