It’s easy for cats to look offended. We can tell when there’s something disgusting on the floor because our cat Troi will sniff, look up at us with a weird look and her mouth half open. We refer to this display as the “open mouth sniff,” and it means she’s found something really gross, so we generally go investigate and clean it up. As it turns out, she’s not just making faces. Troi has a real reason for opening her mouth when she smells something.
A cat’s sense of smell is fourteen times that of a human. In addition to being able to smell with their nose, cats also have a special sensory organ called the vomeronasal organ or Jacobson’s organ. Located in the roof of the cat’s mouth behind the teeth, the Jacobson’s organ consists of two fluid-filled sacs that connect to the cat’s nasal cavity.
Although the cat sort of looks like she’s smiling or grimacing when she takes a big whiff, the act of opening the mouth and drawing up the air to the Jacobson’s organ is called the flehmen reaction. Essentially, the cat is opening her mouth to suck in the air into the Jacobson’s organ and take a really deep sniff of the odor.
It may look like the cat is offended, but she’s probably really enjoying herself. Cats learn all kinds of information about their surroundings through their sense of smell. They mark territory using the scent glands on their cheeks and paws. The glands secrete pheromones, which are chemical substances that stimulate a behavioral response, such as an avoidance or aggressive reaction. Pheromones are also found in saliva, feces, and urine. When cats “spray” it’s another way they are marking territory.
The bottom line is that a cat is getting a tremendous amount of information from your living room. All those pieces of furniture she’s rubbed up against reveal stories of who has been where when. At our house, to our cats, the floor is undoubtedly a veritable novel of smells revealing stories of humans, canines, and felines wandering all over it.
So when Troi graces us with an open-mouth sniff, she’s letting us know that the novel has a particularly exciting moment.