Many cats follow the same routine before sleeping, and yet several aspects of this ritual remain somewhat mysterious to us. This much we do know: Cats sleep an average of 16 hours a day, according to a Nebraska Humane Society fact sheet. Most healthy cats therefore sleep two-thirds of their life away, with the time affected by your cat’s age, its hunger, its sense of security, and even the weather.

The sleep-centered lifestyle revolves around your cat’s ancestral ways. Hunting excursions would interrupt long naps. These were often unsuccessful, requiring conservation of energy. Or if successful, they would promote rest for digestion, similar to how you might feel tired after consuming a filling, meaty meal.

The sleeping ritual often begins with the cat slowly marching around in a tight circle, often kneading as it moves. Kneading is frequently a precursor to sleep, says Kristen Hampshire, co-author of the Cat Lover’s Daily Companion: 365 Days of Insight and Guidance for Living a Joyful Life With Your Cat. She explains that it’s a sign of happiness and security going back to kittenhood, when kittens knead while nursing to communicate, in part, that they are present and OK.

As for why cats move in a circle before going to sleep? Veterinarians at Meisel’s Animal Hospital in New Jersey posted on Facebook that “dogs and cats turn in circles before lying down because in the wild this instinctive action turns long grass into a bed.”

I also have to wonder that cats are thoroughly marking the spot with their scent to perhaps remember it in the future or to appease their senses while they sleep. If someone else invades the spot, the cat would then perhaps be more alerted to the stranger’s scent.

The truth, however, is that no one has fully figured out this mystery. Hopefully future studies on cats will reveal more about their behavior, helping us to better understand our pets.