Cats are amazing creatures. They are independent yet social. They are loving, yet sometimes may be deemed aloof. They are one of the most popular pets in the world, and they have some pretty incredible abilities. One of the things that make cats so special is their heightened senses. Cats have excellent hearing, vision, and sense of touch, and each of these senses helps cats to survive in the wild and to thrive as pets. Among the most celebrated of feline abilities is their highly regarded sense of smell. But just how powerful is a cat’s nose?
The nose helps the cat smell their food, identify other cats, and even find their way home. Some say that a cat’s sense of smell is so strong that they can even detect health problems in other animals. But just how good is a cat’s sense of smell? Can cats smell better than humans? If you are interested in knowing the truth about a cat’s keen nose, then continue reading to learn all about it.
Can Cats Smell Better Than Humans or Other Animals?
This theory has faced some major challenges in the past decade, as things are rarely black or white. While it is true that cats devote more of their overall brains to detecting scent than humans, this does not necessarily mean that they are always better at smelling than humans or other animals. Let’s take a look at the science to try to work out what may be going on.
The Relative Size of the Olfactory Epithelium
There are several factors that come into play when determining how well an animal can smell. One of the most important criteria for the established theories on comparative smelling ability is the relative size of the olfactory epithelium. The olfactory epithelium of cats is larger than that of humans, in comparison with the relative size of their body. Many people have taken this to mean that cats are more sensitive to smell than people are.
The olfactory epithelium is a layer of specialized cells located in the nose that is responsible for detecting odors and is made up of three types of cells: olfactory receptor neurons, supporting cells, and basal cells.
The Number of Olfactory Receptor Neurons
Another neuroanatomical measure that is used to theorize that cats may be able to smell better than humans in certain instances is the number of a particular animal’s olfactory receptor neurons. These are the cells in the nose that are sensitive to odors. These neurons have hair-like projections called cilia. When odor molecules bind to the cilia, they stimulate the olfactory receptor neuron, which sends a signal to the brain. The olfactory receptor neuron is part of a complex system that helps animals identify smells. This system includes not only the nose but also the brain. The olfactory system is important for many reasons, including giving animals and humans the ability to enjoy food and avoid danger.
Let’s look at a chart comparing the number of olfactory receptors in animals and humans:
| Species | Number of Olfactory Receptor Neurons |
| Humans | Around 5 Million |
| Dogs | 100-300 million, depending on breed |
| Cats | 200 million and more |
In this comparison, we can see that humans have the lowest number of olfactory receptor neurons at around 5 million, dogs may have as high as 300 million depending on breed, and cats have around 200 or more million olfactory receptor neurons. This will have a significant impact on the sense of smell, but this is where it gets interesting.
The Vomeronasal Organ
Besides the olfactory receptors, cats have a specialized organ called the vomeronasal organ (or Jacobson’s organ) located on the roof of their mouth, behind the incisor teeth. This organ allows them to pick up on fine scent molecules such as pheromones, undetectable to the human nose. If you’ve ever seen a cat curl up their upper lips, especially males which haven’t been neutered, this is called the Flehmen response. This is how they are picking up on scent from females in heat. The vomeronasal organ detects pheromones and other chemical signals, crucial for communication and finding mates.
Is a Cat’s Sense of Smell Measurably Better?
According to all traditional wisdom—and a great number of scientific theories—cats and other animals have a better sense of smell than humans. However, this view is mainly based on the interpretation of neuroanatomical findings when comparing the size of the brains and olfactory organs between humans and other animals. In fact, the concept that larger olfactory bulbs increase the sense of smell based solely on size remains under debate.
What About Humans and Their Sense of Smell?
Neuroscientist John McGann at Rutgers University in New Jersey suggests that humans’ sense of smell may not be as bad as once believed and is not always easily comparable to other species. That being said, numerous studies now suggest that humans have a much better sense of smell than previously thought and that olfaction plays a significant role in influencing a wide variety of human behaviors.
Conclusion
Based on everything we discussed, cats have a profound sense of smell thanks to their olfactory receptors and vomeronasal organs, which help them communicate with other felines, catch prey and find their way around. That said, how strong it is compared to humans and dogs may be an unfair comparison, and science certainly still has a lot to say when it comes to this topic.
- See also: Can Cats Smell Mice?
Featured Image Credit: miezekieze, Pixabay
