Why Do Cats Open Their Mouth After Smelling Something?

Have you ever observed your cat opening their mouth after smelling something? It may seem strange, but there’s a scientific explanation behind this peculiar behavior that you might not be aware of.

To begin with, cats have an extraordinary sense of smell. Their olfactory abilities are 14 times better than ours. But that’s not all; they also possess a specialized organ called the Jacobson’s organ, which is located in the roof of their mouth. This organ enables them to detect even the faintest scents and pheromones that are imperceptible to humans.

Now, let’s address the main question – why do cats open their mouths after smelling something? It’s not just a random quirk or habit; they’re actually utilizing the Jacobson’s organ to further examine the scent. When a cat opens its mouth, it increases air flow through the organ, allowing for a more precise and detailed analysis of the scent.

But wait, there’s more. The open-mouthed expression that cats make after smelling something is known as the Flehmen response. This involves curling back their top lip, exposing their front teeth and extending their tongue to direct the scent towards the Jacobson’s organ. This enhances their ability to analyze it even further.

So next time you catch your feline friend opening their mouth after taking a whiff of something interesting, remember that they’re simply trying to fully comprehend and appreciate the scent. It’s yet another impressive aspect of your cat’s remarkable senses and abilities.

What Is the Flehmen Response?

Don’t be alarmed, your feline friend is simply exhibiting the Flehmen response. This intriguing behavior is not unique to cats, as many other animals also display it, but it is particularly common among our feline companions.

The Flehmen response involves a specific facial expression and action where the cat curls back its upper lip and inhales deeply through their nose. This behavior is a way for cats to better analyze the scent that they have detected. By exposing their teeth and curling back their lip, cats allow scent particles to reach their vomeronasal organ (VNO). The VNO is a special receptor in their nose that helps the cat process pheromones and other chemical signals that are not detected by their regular olfactory system.

But wait, there’s more. When a cat exhibits the Flehmen response, it opens up a special duct in the roof of its mouth called the nasopalatine duct. This duct carries these scents directly to the VNO for further analysis. By opening their mouth and curling back their lip, the cat is able to direct the scent directly into this duct and gain a better understanding of what they are smelling.

The Flehmen response is not just limited to domestic cats. Wild cats like lions and tigers have also been known to exhibit this behavior. Interestingly, unneutered male cats are more likely to display this behavior than females or neutered males. This is because they are more sensitive to pheromones and other chemical signals that can indicate the presence of other cats or potential mates.

How Does the Flehmen Response Work?

Let’s dive into the fascinating world of animal behavior and explore the mysterious Flehmen response. You may have noticed your cat opening their mouth and inhaling deeply after encountering a new scent. But what exactly is going on?

The Flehmen response is a behavior exhibited by cats (and other animals) when they encounter a new scent. It involves them opening their mouth slightly and inhaling deeply while keeping their tongue curled backward. This behavior directs the scent towards the vomeronasal organ (VNO), located in the roof of their mouth, which detects pheromones – chemical signals produced by animals to communicate with each other.

By inhaling a scent through the Flehmen response and directing it towards the VNO, cats can analyze and process more information about the scent. They can determine whether it comes from a potential mate, predator, or rival. It’s like having a superpower to decipher chemical signals that are undetectable by their regular olfactory system.

Interestingly, the Flehmen response isn’t exclusive to cats. Other animals like horses, cows, and dogs also exhibit this behavior. In fact, the word “Flehmen” comes from the German word “Flehen,” which means “to bare teeth.” The behavior was first described in horses, where stallions would lift their upper lip and curl it back while sniffing a mare’s urine.

Overall, the Flehmen response plays a crucial role in animal communication and survival. It allows cats to gather important information about their environment and other animals, identify potential mates or threats, and communicate through pheromones. Next time you see your cat exhibiting the Flehmen response, take a moment to appreciate how intriguing and complex these creatures truly are.

Why Do Cats Exhibit the Flehmen Response?

It’s a curious behavior that looks like a combination of a snarl and a yawn, leaving many of us wondering what’s going on in a cat’s mind when they do it.

The Flehmen response is not unique to cats. Many other animals, including horses and cows, exhibit this behavior too. It’s a way for animals to gather more information about a scent, particularly pheromones produced by other animals. The curled lip helps direct these pheromones towards the vomeronasal organ located in the roof of the mouth.

In cats, the Flehmen response is an important part of their communication and survival skills. Cats are very sensitive to smells and use their sense of smell to communicate with other cats. The Flehmen response helps them detect and analyze pheromones from other cats, which can provide important information about their health, reproductive status, and even mood.

For example, female cats in heat produce pheromones that signal their readiness to mate. Male cats use the Flehmen response to detect these pheromones and locate potential mates. In addition to detecting pheromones from other cats, the Flehmen response can also help cats analyze unfamiliar scents in their environment. This behavior is often seen when a cat encounters a new object or animal, such as a new toy or another cat.

When a cat comes across an interesting scent, they will open their mouth and curl their upper lip, exposing their teeth and gums. This might look like the cat is snarling or hissing, but in fact, it is a natural response to help them better analyze scents.

Overall, the Flehmen response is a natural behavior exhibited by cats to help them better analyze scents and gather important information about their environment. It’s a crucial part of a cat’s communication and survival skills. So next time you catch your cat exhibiting the Flehmen response, remember that they’re just trying to gather information about their surroundings. Who knows, maybe they’ve found a potential mate or a new friend.

To summarize, here are the key points:

What Are Pheromones and How Do They Affect Cats?

Cats produce pheromones in different glands throughout their body, including the cheeks, chin, and tail. These chemicals can be used for marking territory, indicating mating readiness, and promoting a sense of calmness in their surroundings.

When a cat opens its mouth after sniffing something, it’s not just taking a deep breath – it’s trying to better detect the pheromones it has picked up. By drawing in more air, cats can better analyze the scent molecules in the air and understand what they mean. It’s an essential part of how they communicate with each other and understand their environment.

But what’s even more fascinating is that cats may also open their mouths after smelling something because they’re experiencing a strong emotional response. If they smell something particularly exciting or appealing, they may express their enthusiasm through this behavior.

Understanding pheromones is crucial for any cat owner who wants to deepen their bond with their furry friend. By recognizing the importance of these chemical signals in cat communication, we can better care for our cats and help them feel more comfortable in their surroundings.

So next time your cat opens its mouth after smelling something, know that it’s doing much more than just taking a whiff – it’s using its highly evolved senses to navigate its world. And by paying attention to these behaviors, you can gain insight into what your cat is thinking and feeling. Here are some key takeaways about pheromones and how they affect cats:

What Types of Scents Trigger the Flehmen Response in Cats?

This behavior occurs when cats use their vomeronasal organ to analyze scents more thoroughly. While it’s most commonly observed in male cats when they smell the urine of a female cat in heat, there are many other types of scents that can trigger this behavior in our furry friends.

One scent that’s likely to make your cat go wild is catnip. This plant contains nepetalactone, a chemical that can cause euphoria and increased activity in cats. As cats smell catnip, they may exhibit the Flehmen response as they try to analyze the scent more thoroughly. If you want to give your cat a little pick-me-up, try introducing some catnip.

Another scent that can trigger the Flehmen response in cats is pheromones. These are chemicals that animals release to communicate with each other. For example, female cats release pheromones when they’re in heat to attract males. When male cats smell these pheromones, they may exhibit the Flehmen response as they try to analyze the scent and determine the female’s reproductive status.

But it’s not just pheromones that can trigger this behavior. Urine from other animals, particularly predators or potential mates, can also cause the Flehmen response in cats. The strong chemical signals contained within the urine likely play a role in this reaction.

Additionally, strong-smelling foods like fish or meat can also trigger the Flehmen response in cats. Some cats may even exhibit this behavior when they smell unfamiliar objects or substances.

Are Wild Cats Also Prone to the Flehmen Response?

This behavior, commonly known as the “stinky face,” is not unique to domesticated cats but is also exhibited by their wild counterparts.

In fact, the flehmen response is even more critical for wild cats than it is for house cats. Many species of wild cats, including lions, tigers, and leopards, use their sense of smell to hunt, mark territory, and communicate with other cats.

When a wild cat smells something interesting or new, they often open their mouth and curl back their lips in the classic “stinky face” expression. By doing so, they can gather more information about the scent they are smelling, helping them determine the age, gender, and health of other cats in the area.

This behavior is not only useful for communication and hunting but also helps wild cats avoid danger. By carefully analyzing scents using the flehmen response, they can determine if a predator is nearby or if there’s a potential threat in the area.

The importance of the flehmen response for wild cats cannot be overstated. It plays a crucial role in their survival and allows them to navigate their environment with ease. So while you may have seen your house cat make that classic “stinky face,” remember that this behavior is just as important for their wild cousins.

What Are Some Other Ways That Cats Use Their Sense of Smell?

Cats are fascinating creatures with a highly developed sense of smell that they use for various purposes. Let’s explore some of the other ways cats use their sense of smell.

Communication is one of the most important uses of a cat’s sense of smell. Cats have scent glands on various parts of their bodies, including their cheeks, paws, and tail. When a cat rubs against an object or another cat, it leaves behind its scent from these glands. This allows other cats to identify the scent as belonging to a particular cat and can help establish social hierarchy among feline groups. Scent marking is also a way for cats to communicate with other animals and leave behind information about their identity and territorial boundaries.

Cats also use their sense of smell to identify their prey. Their highly developed olfactory system allows them to detect even the slightest scent of prey animals such as mice or birds. This can help them locate prey even if it is hidden or out of sight. Additionally, cats use their sense of smell to determine if food is safe to eat or not, as they can detect spoilage or contamination through their noses.

Furthermore, cats use their sense of smell to navigate their environment and locate resources such as food and water sources. They can identify familiar scents in their environment and use this information to find their way around and locate necessary resources. This ability is particularly important for outdoor cats who need to be able to navigate large areas effectively.

Finally, a cat’s sense of smell helps them detect danger. If they detect the scent of a predator or other potential threat, they may become more alert or take action to protect themselves. Similarly, if they detect the scent of something unfamiliar or potentially harmful in their environment, they may become cautious or avoid the area altogether.

Is There Anything That Can Be Done To Reduce Unwanted Scents Around a Cat?

Luckily, there are several things you can do to reduce these odors and create a fresh and pleasant environment for both you and your furry friend.

Starting with the litter box, this is often the main source of unpleasant smells. Make sure to scoop out waste at least once a day and change the litter completely every two weeks. By doing so, your cat will have a clean and inviting place to do their business.

In addition to maintaining a clean litter box, good hygiene for your cat is also essential. Regular brushing removes loose hair and prevents matting, which can trap odors. Although cats are capable of cleaning themselves, the occasional bath can help remove stubborn odors that may be lingering on their fur.

Keeping your cat’s environment clean is also crucial. Regular vacuuming removes any loose fur or debris that may be contributing to unpleasant smells. Additionally, washing their bedding and toys regularly prevents them from absorbing unwanted odors.

Finally, odor-neutralizing products can be a lifesaver. There are many safe and effective products designed specifically for pet owners, such as candles and sprays that neutralize odors without using harmful chemicals.


In conclusion, the seemingly odd behavior of cats opening their mouths after smelling something has a purpose. This behavior is called the Flehmen response, which allows cats to analyze scents more effectively by directing them towards their vomeronasal organ (VNO). With their exceptional sense of smell, this behavior helps cats detect even the faintest scents and pheromones that humans cannot perceive.

Interestingly, wild cats also exhibit the Flehmen response as they use their sense of smell for hunting, marking territories, and communicating with other felines. As cat owners, understanding pheromones is crucial in building a stronger bond with our furry friends. Recognizing these chemical signals can help us provide better care and create a comfortable environment for our pets.

Maintaining good hygiene for your cat and keeping their surroundings clean can significantly reduce unwanted odors. Regular vacuuming, washing bedding and toys frequently, and using odor-neutralizing products are effective ways to create a fresh and pleasant environment for both you and your feline friend.

In summary, the Flehmen response is not just an ordinary habit but a natural instinct that helps cats analyze scents better.