Do octopuses have dreams? Tiny ones, probably

Footage showing an octopus shifting in colour while asleep has been released by scientists in Brazil, who have published a new study saying the sophisticated cephalopods experience at least two different types of sleep. One of these states, which they dubbed "active sleep," is akin to rapid eye movement (REM) in mammals, birds and some reptiles -- raising the intriguing possibility that, like humans, octopuses experience dreams.