Does your cat occasionally make a peculiar face? Cats lift their lips and hold their mouths slightly open to inhale cat pheromones after giving them a very long time to sniff. The German word “flehmen,” which means “lip curl,” could be mistaken for an aggressive snarl, but it fact depicts a completely normal and tranquil cat habit.

Pheromones
Cats use pheromones, or smell hormones, to interact with one another. Each species generates a unique pheromone that can communicate different messages to other animals, like cats. A cat might, for instance, brush its cheek against something to release pheromones and mark its territory. The gender of the cat is also revealed by pheromones in cat pee.
A cat’s expression changes as pheromones are caught by its tongue and flick-transferred to a duct on the roof of its mouth.
The so-called flehmen response then occurs:
The upper part of the cat’s lips twists, giving the impression of a scowl. All cats use a second sniffing mechanism to evaluate pheromones, but male cats usually display the flehmen kitty smile. They have a sharp eye for sex-related information, so that might be the case even when they are neutered.
Additionally, cats will leave pheromone traces on their favorite individuals. A cat will headbutt or rub its cheek to communicate, “The human is mine.” It’s a sincere sign of love from your feline companion.

Jacobson’s organs
The septum of the nose and the hard palate of the mouth are separated by the vomeronasal or evengans, also referred to as Jacobson’s organs. Jacobson’s organs are related to the hypothalamus, which acts as a kind of switchboard in the brain to send information to other areas. Tiny ducts connect them to openings in the mouth’s roof that are situated beneath the cat’s teeth.

In honor of the Danish physician Ludvig Levin Jacobson, who made the discovery in 1811, the organ is referred to as the Jacobson’s organ. Jacobson’s organs can be found in animals besides cats. Oddly enough, people have them too. According to Dr. Anne Marie Helmenstein “Recent tests have proven that Jacobson’s organ acts as in other mammals to detect pheromones and to sample minute amounts of some non-human substances in the air, even if people do not exhibit the Flehmen reaction,” claims Dr. Helmenstein. There are indications that the Jacobson’s organ in a pregnant woman may be stimulated, which could partially account for an enhanced sense of smell and possibly be related to morning sickness.
The common snake is a vertebrate, a reptile by definition, and probably the most well-known animal with a Jacobson’s organ besides cats.

Flamen’s Response
Numerous animals react to scents in ways similar to the flehmen. Cats and horses are the most famous examples, although giraffes and elephants also frequently display comparable behavior. Hippos, buffalo, goats, llamas, rhinos, pandas, rhinoceroses, and other animals have also been observed to react like flehmen to a scent, usually that of a different species.
If you suspect your pet is sick, contact your veterinarian straight away. When in doubt about your family pet’s health, always see your veterinarian. They have examined your pet, are aware of its medical history, and may be able to offer the best guidance for your pet.
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