An international team of scientists has discovered that domestic cats (Felis catus) prefer to sleep on the left side of their bodies rather than on the right.
The conclusion stems from the analysis of 408 YouTube videos of sleeping cats. In an article published in the journal ‘Current Biology’, they say that in about 66% of the cases the animals appeared to be sleeping on the left side and in elevated areas, above the ground or floor.
This is not merely a whim, but, the researchers suggest, an evolutionary adaptation.
As they can spend between 12 and 16 hours a day sleeping, cats are largely in a vulnerable position for much of the time. Lying on the left side, when they wake up (or are awakened by a potential threat) the left eye can achieve a greater visual range than the right.
The images received by the left eye are processed by the brain’s right hemisphere (and those received by the right eye by the left hemisphere), which is also the part of the brain responsible for reacting to threats, which would enable the animal to flee or prepare for a confrontation more quickly. The right hemisphere also helps the cat detect prey more rapidly and to act in the blink of an eye to capture them.
“Sleeping on the left side may, thus, represent a survival strategy,” the researchers note, who, in doing so, argue that cerebral asymmetries are the factor that determines the position most preferred by cats for sleeping.
