A new scientific study suggests that some spiders are capable of a state similar to a human’s rapid eye movement (REM) sleep, which allows us to dream.
REM sleep, as implied by the name, occurs in creatures capable of moving their eyes. The signs have been noted in mammals and many bird species, but never before in an insect or arthropod.
The jumping spiders observed in the new study have movable retinal tubes that direct their gaze in that manner.
“We report evidence for an REM sleep–like state in a terrestrial invertebrate: periodic bouts of retinal movements coupled with limb twitching and stereotyped leg curling behaviors during nocturnal resting in a jumping spider,” the authors noted in the study’s abstract in the journal Proceedings of the National Academy of Sciences (PNAS).