Ballooning spiders use electric fields to fly

BRISTOL, UNITED KINGDOM — Spiders may not have any wings, but turns out all the eight-legged critters need to fly is a little charge.

Spiders have been known to release long strands of silk to carry them up to 2.5 miles up in the air and over a thousand miles out to sea — a process known as ballooning, according to a new study published in the journal Current Biology.

The common belief is that the strands catch on to the wind and help generate lift. But since it doesn't explain how spiders balloon even on days with light wind, another theory emerged: electrostatic repulsion.

When spiders release their silk, it picks up a negative charge, which repels the Earth's similarly negatively charged surface and creates enough force to propel them into the air.

The University of Bristol study tested the theory by putting the arachnids on vertical cardboard strips in a plastic box, and then generated an artificial electric field.

Sensory hairs on the spiders' feet detected the charge and prompted them to start ballooning. They were able to take-off despite no wind, but dropped when the electric field was turned off.

While the study proved that spiders can fly using electricity alone, scientists believe air currents may still play a role in it. Previous studies have recorded the crawlers raising their front legs into the wind, possibly to determine how strong it is.