Jumping spiders could sleep and dream like humans
Do spiders sleep? New research suggests they just might. And not only that, but their human-like sleep patterns might also mean they dream
READING LEVEL: GREEN
It’s a question that keeps some scientists awake at night: do spiders sleep?
Dr Daniela Roessler and her colleagues set up cameras to capture footage of baby jumping spiders at night to find out.
The footage showed patterns that looked a lot like sleep cycles: the spiders’ legs twitched and parts of their eyes flickered.
The researchers described this pattern as a “REM sleep-like state.”
In humans, REM – or rapid eye movement – is an active phase of sleep when parts of the brain light up with activity. It is closely linked with dreaming.
Some animals, including some birds and mammals, have also been shown to experience REM sleep.
But Dr Roessler, an evolutionary biologist* at the University of Konstanz in Germany, said creatures like the jumping spider hadn’t received as much attention, so it wasn’t known if they got the same kind of sleep.
Dr Roessler and her team dug into the sleep question after she discovered the spiders hanging at night from threads of silk in their lab containers. She had recently scooped up some jumping spiders to study, a common species with a furry brown body and four pairs of big eyes.
“It was just the most unusual thing I’ve ever seen,” Dr Roessler said of the suspended spiders.
She said the research, which was published in the journal Proceedings of the National
Academy of Sciences on August 8, showed the spiders’ overnight movements looked a lot like REM in other species – like dogs or cats twitching in their sleep.
And they happened in regular cycles, similar to sleep patterns in humans.
Study co-author Dr Paul Shamble, from Harvard University, said many species similar to spiders didn’t have movable eyes, which made it hard to compare their sleep cycles.
But he said jumping spiders were predators* that moved their retinas* around to change their gaze while hunting.
Plus, the young spiders had a see-through outer layer that gave a clear window into their bodies.
“Sometimes as a biologist, you just get really, really lucky,” Dr Shamble said.
Dr Roessler said the researchers still had to figure out if the spiders were technically sleeping while they were in these resting states. That included testing whether they responded more slowly – or not at all – to triggers that would normally set them off.
GLOSSARY
- evolutionary biologist: a scientist who studies the development of species
- predators: animals that eats other animals
- retinas: the area at the back of the eyes that receives light and sends pictures of what the eyes see to the brain
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QUICK QUIZ
- What type of spiders did the researchers study?
- What does REM stand for?
- What happens to humans during the REM phase of sleep?
- What made Dr Roessler decide to study whether the spiders can sleep?
- Which journal was this research published in?
LISTEN TO THIS STORY
CLASSROOM ACTIVITIES
1. Write a lullaby
A lullaby is a song that helps babies and children to relax and go to sleep. Write the words for a special lullaby to help a baby spider relax and go to sleep. Use the tune for a lullaby that you know. If you don’t know any lullabies, use your research skills to find some to help you.
Time: allow 30 minutes to complete this activity
Curriculum Links: English
2. Extension
Why can’t the scientists say for certain that spiders have sleep patterns similar to humans? Use information in the story to write a list of reasons.
Time: allow 15 minutes to complete this activity
Curriculum Links: English, Science
VCOP ACTIVITY
The spider who couldn’t sleep
Researchers may have determined that spiders are showing signs of sleep, but poor Sheldon the Spider just can’t seem to fall asleep. He needs your help.
Turn to the person next to you and see if you can discuss three to four different ways that might help someone to fall asleep.
Then together, write a short narrative about Sheldon visiting his friends to get ideas on what he could do to try to get to sleep.
Re-read your narrative to make sure it makes sense and flows.
Don’t forget to use your VCOP skills to add voice and style to the piece.