Feline olfaction and the extraordinary superpower of cat smell

You may think a cat’s main form of communication is vocalizing, but it’s actually much more complex than that. While vocalizations, like meowing, chirping, purring, and body language are all important components of communication, scents, particularly pheromones, play a major role in the communication between felines. Wild and domestic felids have a super power in their dual olfactory systems. The olfactory membrane space in cats is 4:1 compared to humans, where information from the smell receptors is transmitted to and processed by the olfactory lobe in the forebrain. The second method of scent detection sits at the roof of the mouth in the vomeronasal organ (VNO), also known as the Jacobson’s organ. So what role do pheromones play?

Pheromones are chemical signals spread by individual animals that can influence behaviors or biological processes in other individuals of that same species. For pheromones and scents to play such a major role in feline communication, felines must have a superior sense of smell. Domestic cats have twice as many scent receptors in their nose as humans, and can smell about 14 times better than humans. And as mentioned above, their sharp sense of smell doesn’t only come from their nose. Domestic cats and wild felids have an additional smelling system called the vomeronasal (VNO) organ. The VNO organ is connected to the nasal cavities and is located on the roof of the mouth. This organ is present in many other species, including snakes and horses. This two-pronged smelling system enables felines to communicate much through scent, with the VNO organ playing an essential role of enhancing detection of pheromones in the vicinity of the cat.

When cats smell something particularly interesting (i.e., territorial messages from another cat), they open their mouth and curl their lip in a gesture called the flehman response. The term ‘flehmen’ is a German word meaning “to curl the upper lip”. If you’ve ever seen your cat making a funny face at an interesting smell, that’s most likely them exhibiting the flehman response. They’re opening their mouth to draw in scent molecules, especially pheromones, and further investigating the smell using the VNO organ. 

Cats spread their pheromones and scents through saliva, urine, feces, and glandular secretions, and these pheromones are most common in areas they frequent. For example, when a cat rubs its chin and cheeks on objects, it leaves behind a pheromone that marks the area as safe and familiar to that individual. Felines use pheromones to mark territory, allowing them to communicate from greater distances, which allows individuals to avoid each other when needed and reduces the chance of life-threatening conflict over territory. Wild felids, including tigers and pumas, use pheromones to detect or attract potential mates, to recognize related individuals, and to communicate to and soothe kittens. The VNO organ allows cats to detect these pheromones and respond appropriately. Research suggests that a damaged VNO organ can increase aggression between cats, likely due to a breakdown in communication.

Further research into cats’ ability to smell and communicate using scents is needed. Domestic cats’ strong sense of smell has drawn attention to them as potential candidates for detecting cancer and other diseases in humans, though research in this field is still emerging. Manipulating pheromones can affect the behavior of the felines that smell them, potentially deterring them from areas or increasing social cohesion. As wild felid conservation becomes a more and more pressing issue, learning how to affect felid behavior through pheromones may be an important tool for conservation efforts in the future.

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