There is a centuries-old mystery that is known as ballooning, which spiders have been taking advantage of to fly around the world. On October 31, 1832, a young naturalist and now world-famous scientist Charles Darwin walked aboard the deck of the HMS Beagle. He realized they had been boarded by hundreds of tiny red spiders. Yet how was this possible? They were over 60 miles away from the shore. This meant the creatures had somehow floated over from the Argentinian mainland.
Spiders, of course, do not have wings, but they can take to the air quite easily. They will climb up high to an exposed point, then using strands of silk they just float away. The behavior is known as ballooning and it allows spiders to easily get far away from any potential predators. And it also makes it possible for them to make their way to a new land where resources may be better. No one understands how it works exactly, but it is an amazing way to travel. Spiders have been found two and a half miles up in the air, or even 1,000 miles out to sea.
The common theory is that the silk is dragged in the wind and spider simply gets pulled around behind it being so light. However, this doesn’t exactly make much sense, the reason being that spiders only do this during light winds. How does a light breeze carry the biggest spider specimens? Even Darwin himself found the process of spiders flying quite inexplicable.
Erica Morley and Daniel Robert have put forth a theory, the two researchers from the University of Bristol, have shown that spiders can sense the Earth’s electric field. And they can use this electric field to launch themselves into the skies. You may not know it or even see it yourself, but every single day, over 40,000 thunderstorms crackle turning the Earth’s atmosphere into a giant electrical circuit.
This is flight by electrostatic repulsion, the spider’s silk pick up negative charges which repel them forwards into the air. Wind does still play a part, with spiders using their leg hairs to gauge how strong the wind is before deciding to balloon themselves into the air.