Hepper blog

Search our database of over 9,984 posts with up-to-date information from our experts and veterinarians.

Hepper is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Flehmen Response in Cats: Vet Verified Facts

By Lorre Luther · Reviewed & fact-checked by Dr. Karyn KanowskiVet Approved
Dr. Karyn Kanowski
Reviewed & Fact-Checked byDr. Karyn KanowskiVeterinarian
Karyn has lived in the UK for the past 10 years after moving from Queensland, Australia. In 2010, she graduated from The University of Queensland School of Veterinary Science, and also holds a Bachelor’s degree in Zoology. Karyn is passionate about using evidence, experience, and owner collaboration to provide the best solutions for pets, and believes in making reliable information about animal health accessible to all. She shares her home with 5 cats, 4 dogs, and 1 husband, and when she is not practising as a veterinary surgeon, she spends her time writing, gardening, and cleaning up pet hair!View authorThe information is current and up-to-date in accordance with the latest veterinarian research. Read about our vets
Share
Ask us a question in the comments
cat's mouth

If you have ever seen a cat take a quick sniff of something and then pull their lips back in a grimace, you may have wondered what was happening. That second, slightly open-mouthed sniff has a name; it’s called the Flehmen response. Cats do it to draw scent molecules into their mouths and into direct contact with something special scent organ called the vomeronasal organ, which is located in the roof of the mouth, behind their front teeth, and that connects directly to the brain. Using this method, cats can pick up information about the health and reproductive status of other animals. It’s a go-to reaction when cats want to gather more information about their environment smells and other animals. using their powerful olfactory abilities.

What Is the Flehmen Response?

The Flehmen response is a way of gathering more information from about scents. Cats rely heavily on their sense of smell to understand and move through the negotiate their world. Part of the reason the feline sense of smell is so good is that it utilizes relies on two organs. In addition to their noses, which are packed full of millions of scent receptors, cats also have vomeronasal or Jacobson’s organs dedicated to picking up subtle pheromones that are undetectable to humans.

Feline vomeronasal organs are located in the roofs of the cats’ mouths,— just behind their tiny front teeth. When cats open their mouths and sniff, they draw scent molecules over their vomeronasal organs, allowing their brains to interpret information directly about other cats’ health and reproductive status.

What Type of Information Does the Vomeronasal Organ Provide to the Feline Brain?

Vomeronasal organs are optimized to detect odorless pheromones which contain information about identity, reproduction and health. These chemicals can even allow other cats to pick up on whether an animal feels stressed, aggressive, or friendly.  Adult cats use pheromones to mark territory and find mates, whilst kittens. These chemicals can even allow other cats to pick up on whether an animal feels stressed, aggressive, or friendly. Kittens rely on pheromones picked up through their vomeronasal organs to identify their mothers. If a kitten is placed between two nursing queens, it’ll give the air a sniff and naturally gravitate toward its birth mother.

male Norwegian forest cat with flehmen response
Image Credit: Elisa Putti, Shutterstock

Cats have pheromone-producing scent glands around their whiskers, ears, and foreheads, and they can also be found around cats’ bottoms and on their paws. This is why cats often rub against each other when first meeting. The contact allows both animals to learn more about the other through contact with the other’s pheromones. When cats rub against furniture, they leave behind their scent to mark the territory.

Outdoor cats often scratch to sharpen their claws and leave their scent behind to notify other cats that the area has already been claimed. Feline urine also contains pheromones. Indoor cats often mark their territory by spraying when feeling threatened or insecure due to stress caused by the arrival of a new pet or inter-pet aggression. Outdoor male cats frequently spray to ensure potential competitors know their presence and help females in estrus track them down.

Is the Flehmen Response Only Seen in Cats?

No! It’s also seen in goats, dogs, horses, and big cats like tigers. But only some types of mammals exhibit the response, which varies a bit by species. The feline and canine Flehmen responses differ; dogs often chatter with their teeth when introducing scent molecules to their vomeronasal organs. It’s often seen after male dogs smell a fertile female’s urine.

Jacobson’s organs are found in many animals, including mammals, reptiles, and amphibians. Snakes and lizards both have them, as well as most amphibians. The organ is even present in some humans! Almost all babies have Jacobson’s organs, and they are present in up to one-third of adult humans, although there’s no consensus on whether these are functional or merely vestigial in adults.

Siberian cat with open mouth
Image Credit: Sunykiller, Pixabay

What Exactly Are Pheromones?

Pheromones are a particular type of hormone, which are chemicals used by that vertebrates and insects use to communicate. Hormones are chemical receptors that facilitate communication within the body, often transporting messages between multiple organs and systems.

Insects like ants use pheromones to coordinate activities such as colony construction, and s. Some species use pheromones to signal the presence of danger.

Pheromones also encode information about the reproductive status that contribute to decisions about mating. The ones that provide information about sexual and reproductive health tend to linger longer, and travel over greater distances, than warning and coordinating chemicals.

Frequently Asked Questions (FAQs)

Is the Response More Often Seen in Male or Female Cats?

Intact male cats are more likely to exhibit the response than other pets, as they’re often more receptive to the reproductive information encoded in feline pheromones. But the Flehmen response can be seen in male and female cats.

Do indoor cats exhibit the Flehmen response?

Absolutely. Many cats take a second sniff if their person has been around other animals. Cats can immediately sense something different and go in for more information. The new scent often causes the cat to display the flehmen grimace.

cat close up with mouth open
Image Credit: ClaraMD, Pixabay

Can cats recognize relatives using smell?

Cats can identify their mothers after being separated for months and use smell to identify people and places. Although it is unclear as to whether they recognize familial pheromones as being relatives, they will recognize the scent and pheromones of cats they know. When cats scratch the couch, they are taking care of their claws, and at the same time, having a bit of fun and leaving behind pheromones that create a warm scent of comfort and familiarity.

How Else Do Cats Communicate With Each Other?

Cats also vocalize and use body language to provide information to other cats. Friendly cats often rub against each other and sometimes link their tails together when snuggling. However, angry cats hiss or snarl to tell other animals to back off.

Adult cats almost never meow when communicating with other pets, and it’s generally reserved for feline-human interaction! However, kittens sometimes meow to get their mother’s attention.

Body language is also an essential element of feline communication. Cats use their bodies, tails, and ears to tell others what they think. Happy felines are often relaxed and walk with their tails upright.

Furious cats often have their ears pointed either straight back or to the side. They often arch their backs and have hair that stands on end. Cats scared to the point of aggression sometimes stare at what’s bothering them while swishing their tails.

Conclusion

The feline Flehmen response often resembles a sneer or grimace. Cats exhibit the behavior when gathering more information about a new smell as it draws scent molecules over their vomeronasal organs. Feline vomeronasal organs are located in cats’ mouths, just behind their top front teeth, and form a direct pathway between the external environment and the brain.

They’re designed optimized to detect pheromones, and cats often rely on their sense of smell to identify familiar cats, people, and spaces. It is also how cats learn about new acquaintances and investigate novel locations and environments.

Sources

Featured Image Credit: Piqsels

Get Hepper In Your Inbox

Pet care tips from our vets and experts, straight to your inbox.

List

Select all that apply.

You may opt-out at any time. View our Privacy Policy for more information.

Lorre Luther
Authored by

Lorre Luther

Join the conversation

Ask a question, share your story, or send private feedback.

Rate this post
Required to post. Only our editors see your rating.
Who should see this?

A human reviews every comment before it appears. Your email is never published.

Picked to go with this article

What Is the Jacobson's Organ (Vomeronasal Organ) in Cats? Vet-Verified Facts

What Is the Jacobson's Organ (Vomeronasal Organ) in Cats? Vet-Verified Facts

Have you ever seen cats suddenly make a funny face, as if a smell disgusts them? This may happen around other cats or near a litter box. In fact, your cat’s gr…

Genevieve Dugal
By Genevieve Dugal ·
Why Do Cats Hold Their Mouth Open? Interesting Feline Facts

Why Do Cats Hold Their Mouth Open? Interesting Feline Facts

Let’s face it—our felines make some freakish faces sometimes that might be hard for us lesser humans to understand. When you see a cat holding their mouth open…

Ashley Bates
By Ashley Bates ·
What Is Flehmen Response in Dogs? Vet-Verified Explanation & Reasons

What Is Flehmen Response in Dogs? Vet-Verified Explanation & Reasons

Our dogs often have us in stitches with laughter with their weird and wonderful behavior. They chase their tails, sniff butts, walk in circles, and sometimes a…

Nicole Cosgrove
By Nicole Cosgrove ·
Why Is Your Cat Suddenly Sniffing Everything: 5 Vet-Approved Reasons

Why Is Your Cat Suddenly Sniffing Everything: 5 Vet-Approved Reasons

Cats do many perplexing things, like burying their food or staring off into space at nothing. One of the mysterious behaviors we often hear about is excessive…

Chantelle Fowler
By Chantelle Fowler ·

Keep reading

More stories you might like

Why Do Cats Leave Their Mouths Open After Smelling? 5 Likely Reasons

Cats have many interesting behaviors that we do not always know the reason behind. One of those behaviors is when cats leave their mouth partially open after s…

Nicole Cosgrove
By Nicole Cosgrove ·
Why Do Cats Leave Their Mouths Open After Smelling? 5 Likely Reasons

Can My Cat Smell Other Cats on Me? Vet-Reviewed Facts & FAQ

Cats are known to be quite sensitive when it comes to their sense of smell. They can detect the presence of other cats in the area and even have unique ways of…

Nicole Cosgrove
By Nicole Cosgrove ·
Can My Cat Smell Other Cats on Me? Vet-Reviewed Facts & FAQ

How Do Cats Communicate With Each Other? Vet-Reviewed Body Language, Pheromones & Sound

Cats may not converse in a language that we understand, but that doesn’t mean that they don’t communicate with other cats. Cats have many ways to communicate w…

Kristin Hitchcock
By Kristin Hitchcock ·
How Do Cats Communicate With Each Other? Vet-Reviewed Body Language, Pheromones & Sound

Do Cats Understand Smiles? What You Need to Know!

Some of the best things about being a cat owner are the things they do that make us smile. On the occasions that we greet our favorite felines with these cheer…

Nicole Cosgrove
By Nicole Cosgrove ·
Do Cats Understand Smiles? What You Need to Know!

Why Do Cats Touch Noses With Each Other? 3 Possible Reasons

Even though cats do not communicate with one another like us, their communication methods are highly developed and sophisticated. Interestingly, cats communica…

Nicole Cosgrove
By Nicole Cosgrove ·
Why Do Cats Touch Noses With Each Other? 3 Possible Reasons

Can Cats Smile? Science-Backed Facts & FAQs

We know that our cats have emotions. Their biology and behavior are living proof that this statement is true. It’s easy to know when your pet is upset or conte…

Dr. Paola Cuevas
By Dr. Paola Cuevas ·
Can Cats Smile? Science-Backed Facts & FAQs

Do Cats Have Lips? Feline Anatomy Facts & FAQS

Have you ever taken a good look at your cat's face and tried to make out their different features? One thing you might've noticed is that you can't see any lip…

Nicole Cosgrove
By Nicole Cosgrove ·
Do Cats Have Lips? Feline Anatomy Facts & FAQS

Does a Cat Have Scent Glands in Their Paws? Pheromone Communication 101

The scent is an important mode of communication for a cat. Humans have between five and 20 million scent receptors within their noses, while cats have about 67…

Nicole Cosgrove
By Nicole Cosgrove ·
Does a Cat Have Scent Glands in Their Paws? Pheromone Communication 101