Published: | Updated:

HOW DO SPIDERS FLY?

The aerodynamic capabilities of spiders have intrigued scientists for hundreds of years.

Charles Darwin himself mused over how hundreds of the creatures managed to alight on the Beagle on a calm day out at sea and later take-off from the ship with great speeds on windless day.

Scientists have attributed the flying behaviour of these wingless arthropods to 'ballooning', where spiders can be carried thousands of miles by releasing trails of silk that propel them up and out on the wind.

However, the fact that ballooning has been observed when there is no wind to speak of, when skies are overcast and even in rainy conditions, begs the question - how do spiders take off with low levels of aerodynamic drag?

Biologists from the University of Bristol believe the answer lies in the Atmospheric Potential Gradient (APG), a global electric circuit that is always present in the atmosphere.

The strength of the APG varies as on a calm day with clear skies, when it may reach 100 volts per mertre

On a stormy day or in the presence of charged clouds, the APG can soar to 10 kilovolts per metre.

Researchers exposed Linyphiid spiders to lab-controlled e-fields that were equivalent to those found in the atmosphere

They noticed that switching the e-field on and off caused the spider to move upwards or downwards respectively.

This proved that spiders can become airborne in the absence of wind when subjected to electric fields.

Advertisement

Read articles that feature this panel

Spiders can FLY using electricity in the air, allowing them to travel thousands of miles on windless days

Biologists from the University of Bristol believe the answer lies in the Atmospheric Potential Gradient, a global electric circuit that is...

Most watched News videos