Some spiders travel by ‘ballooning’ through the air.

It’s a bird! It’s a plane! It’s… a spider? As if these little guys weren’t already terrifying enough, some of them can unfortunately become airborne. Although they lack wings, some spiders are able to take to the skies due to a process called “ballooning,” in which they raise their abdomens to the sky and expel silk strands into the air. Those silk strands are then caught up in passing air currents and electromagnetic waves, thus lifting the lightweight arachnid into the air. This ability is typical in younger spiders and smaller species, including crab spiders, as their diminutive size and light weight make it easier to soar upward.

Ballooning allows spiders to travel incredibly long distances. In 1832, naturalist Charles Darwin recorded this unusual behavior, noting that thousands of spiders had boarded his boat despite it being 60 miles offshore. Additional research suggests that spiders can float as high as 2.5 miles off the ground while ballooning and are capable of traversing up to 1,000 miles before landing.