We may have witnessed Spider-man spinning the web and making rounds of the city warding off bad guys. But something new has come up in research and would probably be a nightmare for people with a fear of spiders. In a study which was published on Thursday in the Current Biology journal, researchers have found out that spiders have the ability to fly using the Earth’s electric field. The study involved two biologists from the University of Bristol, namely- Dr. Erica L. Morley, a sensory biophysicist, and Dr. Daniel Robert.
Charles Darwin was the first one to document the flight of spiders in his diary while he was aboard the HMS Beagle in 1832. He observed the spider webs on the ship and the Aeronaut spiders that had flown almost 60 miles across the ocean to land on the ship. Darwin had suspected the role of electrostatic force in such behavior of the spiders albeit without any suitable explanation for the same.
The process in which spiders fly is termed as ‘ballooning.’ In that process, spiders are able to launch from the ground by raising their abdomen to the sky and spinning silk parachutes ranging from 7 to 13 foot that help them to fly. The reason for such behavior was explained in a previous study which emphasized on the capability of spiders to sense wind movement and throwing the silk parachutes at the appropriate time. However, the study did not explain the reason for which the silk threads of the spider do not tangle during the ballooning process. Another study published in 2013 by a physicist at the University of Hawaii, Peter Gorham, facilitated a theoretical background for the role of electricity in the ballooning process.
The study was carried out by exposing Linyphiid spiders to controlled electric fields which mirrored the Atmospheric Potential Gradient (APG) that is a global electric circuit always present in the atmosphere. It was observed that when the electric field was switched on and off, the movement of spiders changed from upwards to downwards. Dr. Morley stated that this behavior of spiders was initiated by electric fields and the tiny hairs on the legs of spiders known as trichobothria could sense the electric fields for initiating the ballooning process. The lack of tangling in the spider web strands during the ballooning process could be explained by the development of a negative charge in the strands that are repelled by the negative charge on the ground.