Here’s how it works. From the top of a platform (like a blade of grass), the spider faces the wind. Standing in a “tip-toe” position, with its abdomen pointing toward the sky (like the lower spider in this picture), it releases a stream of silk from its spinneret. (The picture, although of an adult spider, allows you to clearly see silk thread coming from two spinnerets.)

Once the wind catches a thread, the spiderling leaves its launch pad. Sometimes they “fly” for hundreds of miles. It isn’t just baby spiders who balloon, however. Smaller adults, and “immatures” of larger species, can also position themselves to travel with the wind.

Charles Darwin, during his explorations, saw a large group of spiders land on his ship, the Beagle. At the time, the ship was sixty miles off the coast of South America. Ballooning spiders have even been seen by airplane pilots flying at about 10,000 feet.

Allen Dean, a spider expert at Texas A&M University, describes how ballooning takes place:

Spiders use their silk as a way to disperse. A variety of spiders use their silk as a simple parachute to carry them from one place to another. Light winds and rising thermals favor spider dispersal in this manner. When the wind currents catch the threads the spiders release their launching pad and off they go.

Walt Whitman, the famous poet, described such an event in his 1868 poem A Noiseless, Patient Spider: