Do you ever catch yourself just gazing at your cat while they’re sleeping? Whether they’re curled up on your lap, they’ve contorted themselves into the strangest sleep position, or they’re simply purring away, sleeping cats are seriously cute.
One thing you may have noticed is that your cat likes to sleep on their left side when they’re in one of the best cat beds or snoozing on the couch. A new study has found that cats prefer to sleep on this side, with researchers from Italy, Germany, Canada, Switzerland, and Turkey working together to find out more about their sleeping habits.
The team around Dr Sevim Isparta and Professor Onur Güntürkün wanted to find out whether cats prefer to sleep on a particular side. So, they analyzed several hundred YouTube videos of sleeping cats.
Publishing their findings in the journal Current Biology, they reported back on the 408 videos they viewed. In all videos, a single cat needed to be clearly visible with their entire body sleeping on one side for at least ten seconds. Only original videos were used, with modified or flipped clips excluded.
Two-thirds of the videos showed cats sleeping on their left side.
The researchers consider sleeping on their left side to have had an evolutionary advantage for cats – helping them hunt and escape after they wake up. Cats, of course, would be pretty vulnerable while asleep in the wild, and they sleep for at least half the day, so this makes a lot of sense for them.
Cats who sleep on their left side perceive their surroundings with their left visual field. This is processed in the right hemisphere of the brain, which specializes in spatial awareness, the processing of threats, and the coordination of movements allowing the animal to escape.
Essentially, if a cat sleeps on their left, visual information goes to the right side of their brain, which is best at processing it.
"Asymmetries in behavior can have advantages because both hemispheres of the brain specialize in different tasks," explained Professor Güntürkün.
The researchers summarized: “Sleeping on the left side can therefore be a survival strategy.”
Read next: Why does my cat sleep by my head?
