Spiders use electricity to fly

If you’ve read or watched Charlotte’s Web, you might remember the scene where hundreds of baby spiders fly away from the farm on their webs. This technique, used by many spiders, caterpillars and mites, is called ballooning.

You might expect that the spiders use the wind to balloon, like flying a kite. However, Dr Erica Morley and Professor Daniel Robert from the University of Bristol in the United Kingdom have a different explanation. Their studies have shown that spiders can use Earth’s natural electric field to launch themselves into the air.

Both the Earth’s surface and spider silk are negatively charged, so they repel each other. This lifts the silk into the air, carrying the spider.

This doesn’t mean wind has no effect on ballooning, though.

“In nature there will always be an electric field and at least some wind,” says Erica. “So next we need to find out how wind and electric fields together get spiders into the air.”

This article was published in Issue 28 of Double Helix magazine (https://www.csiro.au/en/Education/Double-Helix). Copyright for this article is held by CSIRO.