octopuses

When octopuses snooze on the seafloor, their skin sometimes pulses with an array of colors, and at other times, they become pale and plain. These alternating patterns mark two distinct stages of the octopus sleep cycle, a small study suggests. During “active sleep,” when an octopus’s skin ripples with dazzling colors, the cephalopod may experience something similar to our rapid-eye movement (REM) sleep, the authors wrote in the study, published March 25 in the journal iScience. Humans do most of their dreaming during REM sleep, but for now, we don’t know if cephalopods also drift off to dreamland — or … Read more