I’ve always been curious about a cat’s ability to purr.

In researching the subject, I found there are two theories. One is that a cat can manipulate and vibrate their larynx to make the sound. Another claims the vibration from purring is due to blood flow in the throat area. Although there is speculation on the matter, veterinarians tell me they “still have no idea how felines produce the sound.”

According to Feline Anatomy, in a 2002 study, it was reported that true purring is only seen in the scientific families of Viverridae. This is comprised of 15 genera, which are subdivided into 38 species. Among the family, mammals with the capability of purring include mongoose, bobcats, mountain lions and of course house cats, just to name a few. The mechanism might vary with a variety of species.

Although scientifically unknown, the essential part of purring lies in the vocal cords – the laryngeal muscles, the diaphragm and the glottis, a part of the larynx, a slit-like opening between the vocal cords. When a cat manipulates the vocal cords, it makes the various vocalizations or vibrations that the animal is capable of producing.

We might not know exactly how they do it, but we might also ask, “why?” It’s assumed it is because the cat is happy and content, or that they’re upset, nervous and ready to fight. A true dualism. But I prefer to think cats are happy and content when they purr. I’ve never heard any of my cats purr when stressed or angry. They just hiss and take a few layers of skin cells with them.

Obviously not all cats are identical, and it was stated in a National Geographic documentary that the largest cats that can produce “purring” are mountain lions. In my opinion, a cat is a cat is a cat, no matter what. But who knows? I definitely do not have the scientific background of the experts.

Many reports I’ve read reference a cat’s ability to heal human ailments. I had such an experience with my cat, Howie. I rescued him as a small kitten from the back of someone’s El Camino in a parking lot. He sat unprotected in the bed of the truck in freezing conditions and 4 inches of snow.

After recovery from the horrible state I found him in, he learned to trust, love and curl up on top of my head when I was sleeping, and purr endlessly. Any headache or stress would completely disappear.

I loved when he wanted to sleep on my head. His purring was magical. Unfortunately I lost him a couple of years ago at the age of 16. To date, I haven’t found another cat that is willing to sit on my head, let alone purr while sitting on it. Howie would have been a good candidate for a (pardon the pun) CT-scan to witness how he purred because he rarely stopped.

I wish I’d thought about that sooner. Any time I took him to the vet, they had to run water in their sink to get him to stop purring so they could listen with the stethoscope. An opportunity was certainly missed.

Cats are amazing animals, whether small, medium, big or super huge. What would we do without these beautiful, magical creatures? I just wish they’d give up the secret of their unique ability to purr. Hopefully someday, someone will discover the answer.

Mari Carbajal is a docent-naturalist at the Placerita Canyon Nature Center.