The skin that moves while the animal sleeps
In 2021, researchers at the Okinawa Institute of Science and Technology filmed sleeping octopuses and watched something that had no clean explanation: the animals' skin began to pulse with colour. Waves of white, orange, and dark brown rolled across their bodies in rhythmic bursts, lasting anywhere from a few seconds to a minute, before the octopus settled back into stillness. The octopus was not awake. Its eyes were closed. Nothing in its environment had changed.
