All animals are particularly vulnerable when they sleep. Cats sleep 12–16 hours per day and prefer elevated places where an enemy must approach from below. Now it is also proven that they have a favorite side when they lie down.
To come to that conclusion, researchers in five countries have studied 408 cat videos where you can see a single cat sleeping on its side for at least ten seconds. Only original films have been used, clips that have been mirror-reversed or manipulated in other ways have been sorted out.
In two-thirds of the films, the cats were lying on their left side when they slept.
The researchers' conclusion is that it is a survival strategy. Cats that sleep on their left side perceive their surroundings with the left part of the field of vision when they wake up. That information is handled by the right brain hemisphere, which is specialized in spatial perception, processing of threats and rapid escape. In a cat that sleeps on its left side, information about approaching predators or prey thus goes directly to the brain hemisphere that is best at processing it.
The study, which has been published in the journal Current Biology, has been conducted by researchers in Italy, Germany, Turkey, Canada, and Switzerland.
