How Do Spiders Sleep?
Spiders sleep in a different way than humans. They do not close their eyes, but rather have a special rhythmic cycle that is less active during the day.
Some spiders are even known to overwinter. When the weather gets cold, they enter a dormant state and drop their metabolic rate. This helps them conserve energy.
While sleeping, they are still aware of their surroundings and may even react to predators. However, it is likely that they do not dream.
In a recent study, researchers tried to determine if spiders have sleep phases. The researchers inserted electrodes into spiders without killing them. As the scientists observed the spiders, they noticed a certain kind of behavior that is similar to rapid eye movement sleep.
During REM sleep, almost all mammals and birds go into a state of sleep. Scientists believe that spiders can be in REM sleep, but do not know whether they can have a dream.
One study filmed jumping spiders at night. Baby spiders were twitching their legs, showing signs of sleep. These jumping spiders also had four large eyes.
After the researchers saw this behavior, they decided to film resting arachnids. Daniela Roessler, a behavioral ecologist at the University of Freiburg in Germany, began filming.
While the results were promising, more research is necessary to prove if spiders have sleep phases. Testing the responses of spiders to movement will help scientists further determine whether they are asleep.
Many spiders are known to suspend themselves from a tree. Alternatively, they may be waiting for food.