What Smells Do Cats Hate

What Smells Do Cats Hate: Sniffing the Feline Way

Smells can affect the behavior of felines. This is tied to a cat’s superior sniffing ability. Having evolved through domestication where they encountered varying smells not common in the wild, their olfactory preferences had to evolve too. So, what smells do cats hate?

A historian called Plutarch once noted that when it came to domesticated animals, cats were the pinnacle of cleanliness. This kind of top-notch cleanliness, to a higher degree, is due to the fact that your feline pal hates bad smells.

It is important to learn more about the smells that cats hate so you can keep your cat from having contact with them, thus preventing stress.

We have investigated certain smells that are unwelcome to most cats. We have also looked at the science behind the feline olfactory mechanism. It’s good to note that every cat is unique; some can tolerate smells that seem unfavorable to others. Another thing—can bad smells have a negative impact on your kitty’s life? Read on to find out.

The Cat’s Olfactory System

cats nose

You need to first understand the feline’s olfactory system to get why they hate some odors. Your kitty’s nose is a precise instrument with 45 to 80 million microscopic olfactory receptors. These are used for recognizing and processing different smells. In comparison, humans only have 5 million receptors.

This makes the feline sense of smell fourteen times stronger than yours. Their olfactory epithelium—the tissue responsible for detecting smells—is measured at 20cm2, while that of humans ranges between 2 and 4cm2.

Additionally, your furry friend’s nasal organs are much bigger than that cute button nose you see on the outside. Unlike ours, her olfactory system is spread throughout her head.

That’s not all; there are variants of proteins called VIR proteins used for smelling. Humans, dogs, and cats use them to differentiate smells. Surprisingly, humans only have two variants. Dogs, the sniffing kings, have just 9. Cats have 30!

Given the above points, it’s easy to see why a cat’s sense of smell is important to them. So, what organs do cats use for smelling?

Felines mainly use their nose for smelling. The nose helps them in communication, social interaction, sexual reproduction, as well as survival. It is stronger than the mouth—the other organ used for breathing.

However, cats also use their mouth for odor detection. You may have noticed your cat breathing with a slightly open mouth—the gesture that makes her look like she is wearing a smile or grimace. Well, that’s how she draws odors through her mouth to the Jacobson’s organ (vomeronasal organ) for processing. This mouth opening process is called a flehmen response.

The Jacobson’s organ is located on the upper side of the mouth, just behind the upper incisors. It has ducts which lead to the nasal cavity that is connected to the brain. To detect harsh chemicals and bad smell, this organ uses brain-connected nerves.

The interesting thing about this organ is that it has strong receptors that pick up odors that are undetectable to humans; if something is odorless to you, it could be pungent and unfathomable to your cat.

Other functions of the Jacobson’s organ include:

  • Newborn kittens use it to differentiate nursing dams at birth. This helps them to find their mother’s milk during birth. You may have noticed that even with two nursing mothers, a kitten will use her sense of smell to correctly seek out her mother.
  • It is used by male and female cats for the identification of pheromones. This communicates if a partner is ready for mating.

In a cat’s smell detection system, the nose and the Jacobson’s organ work as a team. They provide felines with delicate sensibilities that are unachievable if they work as stand-alone systems.

Natural Smells That Cats Hate

Among the smells floating around in a cat’s environment, many come from natural sources. The smells could be from plantations for barn felines or potted plants for apartment dwellers. Flowers that you keep around to fill the air with lavender or rosy scents could also be unwelcome to your furry roommate.

The same goes for plant-based body sprays, hair, and skincare products. These linger long after application, and as earlier noted, cats can detect even the faintest odors.

This means that whether you spray your home with the mildest scents or have just a small garden in the backyard, your cat will definitely detect the odors. So which plant smells should you be wary of?

#1: Lavender


Most people love the smell of lavender. But does this beautiful, aromatic plant pose a threat to our feline friends? Reliable veterinarians stress that it does if not applied in moderation in a house with cats.

The smell of lavender is hated in the cat world and for a good reason; it is not entirely safe. As an alternative, in your home, you can use diffused lavender oil instead of fresh flowers to avoid high concentrations in the house.

#2: Spices

Humans love the smell and taste of most spices. Mustard may smell great to you, but it is revolting to cats. Cats detest the smell of spices as they are very strong, and are mostly mixed. They have been associated with breathing difficulties in cats and irritation when they come into contact with the skin.

A cat’s nose detects pepper and chilli peppers as toxic. In high concentrations, the smell of pepper can even affect people’s eyes and breathing. Now imagine the effect it has on cats whose sense of smell is vastly superior to ours.

Hot pepper contains capsaicin, which is instinctively avoided by cats. Cayenne pepper also sends cats running. However, not all pepper is bad to cats; the sweet aroma of bell pepper is loved by cats

Strong smells of pepper bring about sneezing fits in cats. If her fur is exposed to the particles and she licks it, it may incur high vet costs to treat her for bladder infections.

See Also: Cat Coughing and Sneezing

#3: Bananas

cat smelling Bananas

Bananas have a lot of potassium and are very tasty to humans as well as most animals. This, however, doesn’t mean that they are also pleasant to cats.

Ripening bananas have a strong chemical in their peels, called ethyl acetate. This smell has a lot of acetone, which cats hate. So, cats don’t hate bananas; they just hate the odor coming from the peels.

#4: Citrus


This type of smell could be from lemon, oranges, or lime. The aroma is very repugnant to felines. Citrus fruits contain limonin, volatile oils, and high acid concentrations which are bad for felines.

Contact with peels from citric fruits cause skin irritations in both cats and humans. You may have already noticed that your four-legged friend will keep her distance when you are enjoying an orange or slicing lemons.

The good news is that most cats will avoid citrus on their own after smelling it; you need not worry about citrus poisoning. While our furry friends are curious about everything, they are wise enough to stay clear of citric fruits.

#5: Onions and Garlic

All members of the onion family have a strong smell loathed by most animals, cats included. Onions and garlic are very repugnant; they send a cat’s olfactory system reeling.

Strong concentration in the air can cause your cat to even loose appetite. Additionally, they shouldn’t be used in a cat’s food as they are poisonous to cats.

See Also: How Much Garlic is Toxic to Cats

#6: Pine

Most cat litter is mostly composed of sand. This is because the granules are small in size and produce very little dust. Most cat owners use some form of odor control to keep the smell of cat waste under control.

However, since it’s common for some cats to reject artificial litter, pine is sometimes used. If the intensity of the pine smell is too much in the box, though, your cat will similarly avoid it.

#7: Eucalyptus


Most cats are averse to the smell of eucalyptus; even worse, it is toxic to them. The smell of essential oils from the plant is also toxic to cats. As a matter of fact, eucalyptus oil is used as a cat deterrent in most homes to keep away strays.

#8: Mint and Menthol

Mint and methanol are considered abrasive by felines. If they could talk, they would claim it to be one of the most pungent smells they have ever encountered. Just a small sniff will send your cat into sprint mode.

However, catnip (a member of the mint family), has a hallucinogenic effect on cats and some felines really love it.

See Also: How to Give a Cat Catnip

Chemical Smells That Cats Hate

Cats hate artificial smells more than natural smells. These smells come from household items that you use on a day to day basis. If you did not know, here are smells that your kitty might not be able to stand.

#1: Soaps

Cats can encounter these smells when soap is used to clean their litter box, food bowls, or during house cleanings. Also, some owners bathe their cats, but as a rule of thumb, avoid using strongly scented soaps.

Unlike humans, cats live and operate close to the ground. If you wash your floor with harsh chemicals, they will pose breathing problems to her. Remember, even if soap stops smelling to you, it may continue to be detected by your furry housemate for a long time.

#2: Deodorants and Sprays

Your cat encounters these smells when you use strong deodorants or sprays and then interact with her. These products have chemicals that can be very unpleasant for a cat’s nose. When you use them, open the windows to help in reducing the concentration in your house.

#3: Drugs

Most drugs have very strong odors because of their ingredients. A cat’s sense of smell is so strong that they can smell drugs in another cat’s body; this is why a cat will sometimes avoid her feline friend who has just come home from the vet’s. As much as possible, you should keep drugs far away from cats.

#4: Household Cleaners

Household cleaners contain a wide range of chemicals. Most of them have smells greatly hated by cats.

Besides the smell, when you use them in your home and especially in high concentrations, it is very likely that your cat will come into contact and ingest them through licking them off her fur.

It’s important to use gentle cleaners and, if possible, mildly scented or unscented ones. Afterwards, ensure that you rinse them off thoroughly.

Other Smells Hated by Cats

Besides plants and chemicals in and around your home, there are other smells that your cat is bound to detect and hate. These include:

#1: Spoiled Fish

Most people hate the smell of fish, even if they don’t hate the taste. Bad fish is very smelly; it is even poisonous. The smell is several times worse for cats. It’s no wonder no cat will go near bad fish. Notably, most cats hate spoiled food, no matter how good it is when fresh.

#2: Other Cats

Cats mostly recognize each other by smell. It is one of the ways through which they build relationships. If you, for example, have Cat A and B and you take B out to another location, and then afterwards bring her back, she might have picked up the smell of the place she was in.

Cat A might resent her because even though she looks familiar, she doesn’t smell familiar. Cat A might require time to get used to Cat B.

The smell of a new cat in your home might also affect your current cat. This is because most of them are very territorial and the smell of a new cat is unwelcome.

See Also: How to Introduce a New Kitten to a Cat

#3: Dirty Litter Boxes

kitten and Litter Boxe

Do you hate a dirty bathroom? Cats are the same and will avoid a dirty litter box because of the smell. To keep her from doing her business somewhere she’s not supposed to, make sure her litter box is clean and non-smelly. Cats are very clean and will avoid a smelly environment at all costs.

The Use of Smells as Cat Repellents

The above smells can be used as cat repellents. They can be useful in keeping cats from approaching certain areas. That said, artificially manufactured repellents contain chemicals that could harm cats in the long run. It is advisable to use natural homemade repellents.

Remember, repellents should be moderated and monitored to ensure no harm comes to your kitty.

The Effects of Bad Smells on Cats

Have you ever been exposed to smells that you consider bad or pungent? Besides the discomfort, bad smells can greatly affect your breathing system and also trigger other symptoms such as headache and nausea. Your cat is no different; her tolerance for bad smells can be stretched beyond limit to produce the following effects:

#1: Stress

If your cat is continually subjected to some of these smells, she could become stressed. Stress in cats comes with a host of other effects that greatly lower your cat’s quality of life.

Signs to watch out for include excessive grooming, excessive scratching, urinating away from the litterbox, and lack of appetite among others.

#2: Breathing Problems

Strong odors from sprayed essential oils and deodorants can impair a cat’s breathing system.

Bad and strong smells from chemicals are unhealthy and unpleasant to cats. But they are worse in that they also affect the cat’s breathing.

Strong odors bring about a consistent series of very rapid short inhalations followed by short exhalations; this forces air into a space in your cat’s body which is used for trapping the inhaled air.

So, instead of the air getting passed to her lungs for it to be injected in her blood, it rests in this space so as to allow the odor molecules to interact with the scent receptors first. This clearly puts stress on a cat’s breathing system.

Other signs of health problems include vomiting and drooling.

Why Don’t Cats Hate Smelling Each Other’s Rear End?

It is a fact that cats sniff each other’s butt. It’s natural in their world but strange in yours. Why do they do it? Why do they hate a wide range of smells yet not hate butt smell?

To cats, smells are a form of chemical communication tool. The answer to cats smelling each other’s butt and not finding it unpleasant is anatomical.

They do it as a greeting in which a lot of unique information about each other is passed. It gives information about a cat’s aggressiveness, health, and mating habits among others. It is also a form of cat identification that enables cats to recognize if they’ve met previously.

That’s not all; this sniffing is also used to express dominance. A dominant cat will sniff initially while the submissive cats wait for their turn.

Wrap Up

Cats hate a variety of smells that range from plants, chemicals, to other sources in and around your home. Unfortunately, your experience with the potency of these smells might just be the tip of the iceberg compared to your cat’s. Why? Your cat smells 14 times better than you! This can greatly work against her.

As a cat owner, it is your responsibility to ensure that your home offers a pleasant olfactory experience for you and your cat. While it may not be possible to get rid of all smells in your home, you can definitely minimize the interaction between your furry friend and the sources of these smells.

This might mean totally avoiding or cutting back on the use of some of your favorite scents. Your cat will thank you for it.

Has your cat ever come into contact with any of the above smells? What was her reaction and what did you do about it? Did you find this article helpful? We would love to hear from you. Share your comments below, and don’t forget to check out our next article on how do cats see to learn more about their other amazing sense.

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