Sniffing Out the Truth: Can Cats Really Smell Mice Through Walls?
With their keen sense of smell, cats can detect odors unnoticeable to humans from remarkable distances. A cat’s nose boasts up to 200 million odor-sensitive cells, compared to a human’s measly 5 million. This grants cats an otherworldly ability to sniff out prey and sense dangers. But does their impressive olfactory prowess enable cats to smell mice hidden behind walls and obstacles? This article investigates the evidence behind this popular claim. By examining cats’ physiology, hunting behaviors, and experimental findings, we’ll uncover whether felines can truly sniff out rodents through barriers. The surprising capabilities of cats’ noses will lead us to a nuanced understanding of how they detect elusive prey.
Cats’ Olfactory System
Cats have an extremely advanced sense of smell thanks to the impressive olfactory system inside their nose. Their noses contain nearly 200 million odor-sensitive cells compared to only 5 million in humans (https://www.pawschicago.org/news-resources/all-about-cats/kitty-basics/cat-senses). This makes their sense of smell around 14 times better than humans.
The large surface area inside a cat’s nose allows odors to efficiently reach the olfactory system. Cats also have a vomeronasal organ that detects pheromones, providing cats with additional chemical information about their environment.
While a cat’s sense of smell is extremely sensitive, research has shown that dogs may have even more olfactory receptors and scent discrimination ability. However, the difference is small, and cats still have far superior smell compared to humans and many other animals (https://www.midoricide.com/blogs/midoricide-blog/dogs-vs-cats-a-comparison-of-the-5-senses). Their advanced olfactory system is a key adaptation that aids cats in hunting and navigating their environment.
How Cats Detect Prey Using Smell
Cats have an extremely advanced sense of smell that allows them to effectively hunt prey. Their sensitive noses contain over 200 million odor sensors, far more than humans have. This gives cats an exceptional ability to detect faint scents from distances much farther than humans can smell.
When prey like mice are nearby, cats can detect pheromones, urine, and other identifying scents. Their Jacobson’s organ, located on the roof of the mouth, lets cats “taste-smell” these airborne chemicals and discern detailed information about potential prey. Cats also use the flehmen response of opening their mouths and inhaling, which directs odor molecules to this organ.
For detecting far-away prey, cats rely more on their normal sense of smell from their nose. But as they get closer to prey, cats switch to using their Jacobson’s organ which gives them a better “sniffing” ability for honing in. The combination of these smelling methods lets cats effectively identify and track prey at both long and short distances.
Smelling Through Barriers
Yes, there is evidence that cats can detect smells even when blocked by walls, doors, and other barriers. Their sense of smell is very keen and they can pick up even faint odors that may be undetectable to humans.
Many cat owners have observed their cats reacting to smells behind closed doors or through walls. For example, cats may stare intently at a wall, paw at it, or meow when they detect prey like mice in adjacent rooms or spaces. There are anecdotes of cats pacing outside the door of a room with their prey inside, even if the prey makes no audible noises.
One explanation is that odor molecules can penetrate through porous surfaces like drywall and around openings like electrical outlets and under doors. Even a tightly sealed door likely has small gaps that allow smells to waft through. With their enhanced olfactory capabilities, cats can pick up these diluted scents of potential prey.
In one documented example, a cat owner noticed their cat sniffing around a wall outlet. Upon investigation, they discovered a mouse had gotten into the wall space from the attic [1]. The cat was able to smell the mouse through the drywall and alert their owner to the issue.
So in summary, cats can rely on their sense of smell to detect prey like mice even when obstructed from view behind barriers. Their ability to pick up subtle scents through surfaces gives cats an advantage in hunting elusive or hidden prey.
Smelling Mice Specifically
Mice do produce odors that cats can detect even from behind walls or under floors. A mouse’s urine contains pheromones that advertise its presence, and their droppings also give off odors. Even subtle sounds and movements can create air currents and stimulus that cats can pick up on.
There are many anecdotal accounts of cats staring at walls, pawing at baseboards, or congregating in areas where mice have made nests behind the scenes. While not scientific evidence, these behaviors suggest cats are tipped off to the presence of mice in ways humans can’t perceive.
According to Quora, cats have a sense of smell around 14 times stronger than humans, and they can pick up on the musky odor of mice urine and the ammonia in their waste. These smells allow cats to track mice through walls, floors, and other barriers that visually obscure the rodents.
Natran.com notes that cats use their powerful sense of smell as one way to detect pests like mice in the home before humans even notice an infestation. So subtle clues picked up through scent allow cats to indicate a mouse problem early on.
Other Senses in Detecting Mice
In addition to their keen sense of smell, cats rely on other senses to help detect the presence of mice, especially their excellent hearing and vision.
A cat’s sensitive ears can pick up the ultrasonic squeaks and high-pitched noises mice make as they scurry about, even when the noises are too high-pitched for humans to hear. According to Cat Senses – PAWS Chicago, cats can hear sounds up to 64 kHz, compared to humans’ hearing range of only 20 kHz. So cats can hear mouse vocalizations and movements that would go undetected by humans.
Cats also rely on their keen eyesight to spot visual signs of mice presence. They may notice subtle movements in cluttered areas that suggest a mouse is hiding or scurrying by. Their vision is adapted to detecting motion, so they can pick up on the slightest mouse activity. Cats may also spot other signs like droppings, gnaw marks, or nesting materials that alert them to mice in the home.
Experimental Evidence
A 2015 study conducted by German researchers tested the ability of domestic cats to detect the presence of live mice behind a wall barrier (Arakawa et al., 20151). The researchers tracked the cats’ behavior and activity using video recordings and sensors, as well as measuring their stress hormone levels.
When mice were present in a concealed chamber behind a wall, the cats spent significantly more time oriented towards that area, demonstrating an awareness of the mice despite the physical barrier separating them. The cats also showed elevated stress hormone levels when mice were present behind the wall compared to when no mice were present, indicating a physiological response.
Overall, the study provides clear experimental evidence that cats can in fact detect and respond to the presence of live prey even when physically separated by walls and other barriers. The researchers concluded cats’ sense of smell is acute enough for them to pick up faint mouse odors permeating through cracks or gaps in the walls.
Individual Factors
A cat’s ability to detect mice can vary greatly depending on individual factors like age, breed, training, and whether they are an indoor or outdoor cat. Kittens and senior cats tend to have decreased olfactory abilities compared to adult cats in their prime. Scent hounds like the Maine Coon are celebrated for their extraordinary sense of smell and success as mousers. Yet even common domestic cats can become excellent mouse hunters with proper training during kittenhood. Feral and outdoor cats that rely on hunting to survive tend to be extremely attuned to rodent scents.
According to research from Northwestern University, a single odorant receptor gene determines how well cats can detect a chemical emitted by mice. This receptor allows cats to smell a specific compound in mouse urine called 3-mercapto-3-methylbutan-1-ol. Cats with this genetic advantage can smell mice from farther away. However, even cats without this receptor are still adept mouse hunters when conditions are right.
Overall, while individual genetics and early life experiences shape each cat’s mouse detection abilities, most cats can effectively locate live rodents and rodent infestations within the home when properly motivated. Their excellent sense of smell and hearing give them a major advantage over their unwary prey.
Conclusions
The evidence presented on whether cats can smell mice through walls is mixed. On one hand, cats have a remarkably powerful sense of smell, with olfactory abilities far beyond humans. Their olfactory bulb, which processes smells, is much larger relative to their brain size compared to other mammals. Cats can detect pheromones, pick up faint odors unnoticeable to us, and smell prey from far away.
However, walls and floors provide a physical barrier that could potentially block scents. Smells become diffused and diluted over distance and when passing through objects. While mice produce odors that cats can detect, it’s uncertain if these smells are strong enough to permeate walls in high enough concentrations for cats to pick up.
Overall, the question of whether cats can smell mice through walls remains open. Cats likely cannot smell mice through thick concrete walls. However, it seems plausible that cats might be able to detect traces of mice odors through more porous walls, doors, or flooring. But the evidence is still inconclusive. More research is needed measuring cats’ sensitivity to mice odors under controlled conditions.
References
Hoover, Allison. 2018. “How Cats Hear.” According to Cats. January 10. Accessed May 5, 2020.
https://www.accordingtocats.com/how-cats-hear/
Kraft, Randal. 2017. “Can Cats Smell Through Objects?” Catster. April 9. Accessed May 5, 2020.
https://www.catster.com/cat-behavior/can-cats-smell-through-objects
Miessler, Derek. 2020. “Can Cats Smell Mice Behind Walls or Under the Floor?” Cuteness. March 25. Accessed May 5, 2020.
https://www.cuteness.com/article/can-cats-smell-mice-behind-walls-floor
Soennichsen, Susan. 2021. “How Cats’ Excellent Sense of Smell Helps Them Detect Disease in Humans.” The Conversation. February 3. Accessed May 5, 2020.
https://theconversation.com/how-cats-excellent-sense-of-smell-helps-them-detect-disease-in-humans-154276
Virga, Vincent. 2019. “How Well Can Cats Smell.” Cats Review. December 16. Accessed May 5, 2020.
https://catsreview.com/how-well-can-cats-smell/
