Cats are adorable creatures that can display a host of funny and sometimes absurd antics. One of the most unusual behaviors that cats manifest is the now-famous kitty sneer, grimace, or snarl. Called the feline flehmen response, the animal will look like it’s pulling a stinky face or making a cartoonish look. But aside from its comical look, the flehmen response in cats has a scientific basis. And it’s a good one, at that.
The Classic Look of a Flehmen Response
Whenever an animal executes the Flehmen response, it always try to curl back its upper lip in an attempt to expose its front teeth and gums. At the same time, the animal inhales and often with its nostrils closed. It holds this position for a couple of seconds or so. In many instances, the cat may also take on a slit- or squint-eye look, further exaggerating the “spiteful” appearance.
It is not unusual for individuals who see a cat “flehming” or “flehmening” for the first time to burst into laughter. Some say the flehmen response is like a stoned cat with its mouth open. In some instances, the animal will roll back its lips over the teeth, giving rise to the classic feline sneer.
For some pet parents who are not familiar with the behavior, the response does elicit some vague concerns. A few cat parents may interpret it as confusion, while others may recognize it as a sign of feline disgust. Regardless of how the cat looks when flehmening, there is a sound scientific basis to it. As pet parents, it would also be in our best interest to learn the empirical foundation of such a feline behavior.
Flehmen Response and the Vomeronasal or Jacobson’s Organ
Flehmening cats do not exhibit the behavior because they find you repulsive. They do not do it because they find the food in their bowl to be rotten, or that their litter box is already stinky. It is important to realize that flehming is not a response to something that the feline finds repulsive. As a matter of fact, the flehmen response itself is a kind of sensing behavior.
Biologists say that flehming is similar to sniffing. However, sniffing often involves the use of the nostrils whereby the animal will draw in as much air as it can through the nostrils. Olfactory receptors detect the different scent molecules present in the inhaled air. These receptors then convert the chemical signals into electrical signals for the cat’s brain to decipher.
In flehmening, the nostrils of the cat are not open. Hence, it does not draw in air through its nose. Instead, it opens its mouth in an attempt to expose the openings of a pair of small ducts. These ducts, called nasopalatine canals, are found on the upper palate or the roof of the cat’s mouth. The ducts lie behind the cat’s incisors and connect to the vomeronasal or Jacobson’s organ.
The Jacobson’s organ is a cluster of specialized cells that contributes to the gathering of chemical stimuli from the environment. It is an important component of the olfactory system of reptiles, amphibians, and a large group of mammals. Hence, snakes, frogs, lizards, and other animals can also exhibit the flehmen response.
The vomeronasal organ detects high concentrations of moisture-borne odor particles. These particles can be anything. It can be pheromones from other cats or a very strong scent coming from the garbage can or the kitchen countertop.
It is important to distinguish flehming from smelling or sniffing. Sniffing always involves the drawing in of “airborne” odor or scent particles. These particles go straight into the animal’s nasal chambers where its olfactory receptors pick up the airborne scent. On the other hand, flehming always involves “moisture”-based odor or scent particles. These get drawn through the nasopalatine ducts and into the Jacobson’s organ where the particles get converted into electrical signals.
Flehmen Response: The Cat’s Sixth Sense
When an animal such as the cat executes the flehmen response, it closes its nostrils and draws in air. The odor-rich particles travel all the way to the Jacobson’s organ embedded in the roof of the cat’s mouth. Since the “odor” particles reaching the Jacobson’s organ are rich in moisture, there is another organ that has almost the same function: the tongue.
A cat’s tongue is not that sophisticated, however. The human tongue contains about 9,000 taste buds, allowing us to discern various flavors in the food that we eat. On the other hand, felines only have about 473 taste buds. Dogs, in the meantime, have about 1,700 taste buds. Because of the very few taste buds on their tongue, cats cannot “taste” their food in an efficient manner. However, they make up for this by their heightened sense of smell.
This is where the Jacobson’s organ or vomeronasal organ comes in. Since the structure itself is comprised of highly specialized chemoreceptor cells, it functions to aid the cat’s tongue in deciphering “tastes”.
We mentioned that the ducts that convey odorous particles to the Jacobson’s organ are the nasopalatine canals. What we failed to mention is that the inside lining of these ducts contains secretions that resemble saliva. This is the reason why the air that enters these ducts turns moist. It is the only way the cells of the Jacobson organ will be able to detect the chemicals in the scent.
One thing you have to understand is that these ducts do not open “automatically”. This means the cat or any other animal that exhibits the flehmen response should initiate the action. When it does, it opens the ducts and draws in scent-filled air. As the air passes through the ducts, it draws moisture from the lining of the nasopalatine canals. This leads to the creation of moisture-rich odor particles that reach the vomeronasal organ.
Hence, when a cat performs the flehmen response, it is often a “conscious” effort on its part to “smell” and “taste” the particles in the air. It is also for this reason that biologists, veterinarians, and cat fanciers alike call the flehmen response to be an indication of the cat’s sixth sense.
Implications of the Flehmen Response in Cat Behavior
Whether or not you consider a cat’s flehmen response to be an exercise of feline sixth sense, it does pose a few implications in its behavior.
- Feline Curiosity
Cats are curious creatures and they have to be. They cannot observe with a laid-back attitude, given their predatory nature. As a predator, it is in the cat’s instincts to be very curious about things in its surroundings. It has to use all of its available senses to scan for prey. They may not be sighthounds but their eyes have specialized functions that allow them to scan and focus on a prey.
Their sense of smell is awesome, too. Their nose contains anywhere between 45 million and 80 million olfactory receptors. The human nose, meanwhile, only boasts of 5 million receptors. Scenthounds, like the Blood Hound and the Basset Hound, can have up to 300 million olfactory receptors.
Because the scenting abilities of cats are somewhere between those of man and dog, it uses the flehmen response to better address its curious nature. This allows it to pick up the scent and “taste” the chemicals present in it.
As such, if they see an object on the table, they may initiate flehmening. This is to help them decipher the “taste” of the chemicals emanating from the object. Their olfactory receptors may not be able to pick up airborne scents. Since the air that enters the nasopalatine canals get moistened, the cat will be able to discern the individual scent and taste characteristics of the chemicals.
So, the next time you see your cat flehming, it is because it picked up something very interesting.
- Feline Pheromones
One of the more important implications of flehmening in cats is their ability to communicate using pheromones. These are substances that convey messages or information for cats. Pheromones are ever-present in the cat’s cheeks, head, skin, paw pads, anal glands, and urine.
When a cat rubs its head, skin, or paw pads on an object, it transfers pheromones onto the surface of such objects. When another cat passes by, it picks up these pheromones. It then knows that another cat left the “message” behind and whether it is a friend or a foe. The feline can then decide whether to investigate further or to steer clear and avoid confrontation.
Felines release pheromones for a variety of reasons. It can be territorial, such as the need to mark their territory. They do this to warn other cats not to trespass and to leave the “territory” at once. Pheromones are also perfect for promoting bonding. They can convey messages of trust, calmness, and friendliness.
For most cats, the release of pheromones can be self-soothing. It allows them to feel good about themselves. Cats that live as a group use pheromones to communicate among its members. It lets them identify their colony and to warn “outsiders” to stay out.
Flehmening cats try to pick up these pheromones so that they will know what to do next. If they sense that the pheromones are territorial markers, it would be wise for the cat to stay out of this “invisible” territory. It does not want to get ganged up by a group of hostile cats. In a similar fashion, if it senses that the pheromones are from a friendly cat, then the kitty can proceed to initiate contact.
- Feline Mating
There is a very interesting observation about flehming in cats. Male cats tend to exhibit the response with greater frequency than female cats during the “mating season”. This may sound absurd but it does make sense.
One of the functions of pheromones is in initiating sexual contact. When a female cat is in “heat” and ready to accept potential mates, it releases pheromones in its urine. As the urine evaporates, pheromones mixed with the urine scent get airborne. Male cats, on the other hand, may ‘inhale” the scent, but may not know what it is. As such, it will perform the flehmen response in an attempt to decipher the scent. It then knows if the female cat is ready to mate.
It is not uncommon to see male cats flehmening all the time. This is because they would like to be the first to pick up the scent of a female feline in heat. As such, being the hunters that they are, cats will always be scanning their environment for signs of a cat in heat. Flehmening also allows male felines to zero-in on the location of the cat in heat. If it is too far, then they have to act fast. If the scent is strong enough, then they know that the cat is nearby.
Is the Flehmen Response Something Pet Parents Should be Concerned About
No, the flehmen response is a natural behavior in cats and other animals that want to “taste” the scent molecules in the air. One of the things that make the term quite vague is the use of “response” to it. We all equate “response” to an “effect”. Hence, most will often consider the flehmen response as an effect to something awful, stinky, or repulsive.
As we already discussed, this is not the case. Flehming is an action that a cat or an animal takes to find out more about something. In a way, it is still a response but not in the way that we perceive it. As such, if you notice the cat flehmening, do not be alarmed. What you should try to consider is what is making the cat want to open up its nasopalatine ducts and stimulate the receptors in the Jacobson organ.
The flehmen response in cats is something that is very normal. It shouldn’t concern cat owners one bit. The behavior is nothing more than the cat’s need to find out more about a particular object in its surroundings.