Zoologists have found that spiders can dream

An analogue of the REM sleep phase was discovered by zoologists in jumping spiders, according to N + 1.

Periods of REM and non-REM sleep alternate in humans and in many animals. With REM sleep, brain activity increases, eyeballs move. It is believed that people dream at this time. Animals, presumably, too.

Daniela Rössler from the University of Konstanz undertook to find out whether such periods occur during sleep in spiders.

She chose Evarcha arcuata, which hang upside down on cobwebs at night. At night, spiders are inactive, but sometimes they move their limbs and abdomen, which resembles the manifestations of REM sleep in animals.

But spiders do not have eyeballs and therefore it is impossible to track their movement. Their two main eyes are long tubes with a retina at the posterior end. Spiders move them with the help of special muscles if it is necessary to change the focus.

Zoologists took young spiders for study, the covers of which are still transparent, and filmed their sleep on camera from evening to morning.

It turned out that at this time of the day, the jumpers move their eye tubes, and also twitch their limbs, abdomen and spider warts.

It was found that twitches and rapid movements occur only simultaneously with the rapid movements of the tubes. But zoologists have not observed the reverse pattern.

Thus, they came to the conclusion that spiders have an analogue of REM sleep, and it is possible that they also dream at this time.