Octopuses change colour in their sleep as their brains become active and their skin shows patterns normally seen while they are awake

Octopuses exhibit active sleep with twitching bodies and changing skin patterns. Their brains show electrical signals resembling wakefulness during these active sleep phases. Researchers observed complex skin displays during sleep, mirroring awake behaviors. Brain activity during active sleep was high, especially in learning and memory regions. This active sleep may help octopuses refine motor control of their skin patterns.