Understanding Lateralized Sleeping Positions in Domestic Cats

Both vertebrates and invertebrates show a multitude of left–right asymmetries of brains and behaviors.

Isparta et al. find that two-thirds of cats prefer to sleep on their left side, indicating asymmetry at the population level.

Because the right hemisphere is specialized for threat processing, this asymmetry could increase the likelihood of detecting predators upon waking and thus provide evolutionary advantages.