On February 8, 2013, a Brazilian video, that appeared to show large spiders raining down from the sky, was posted on YouTube. I've included it below, but be warned if you are arachnophobic it could be your worst nightmare. It's a bit creepy to watch and I wondered: Was there an explanation?
Don't Open Your Windows
It seems that in the Spring/Summer of 2012 guests staying at the Chicago Hilton, Magnificent Mile Suites (downtown) were given notice that said in part:
"We request that you do not open your windows in your suite during this time to avoid the annual migration of High Rise Flying Spiders...
A Chicago Phenomenon ~
...Lake Shore high-rises are noticing the annual influx of flying spiders spinning mini masterpieces as high as 95 stories... See Image of notice here
Chicago has Prime Real Estate for Spiders
A 1999 New York Times article about building a high-rise apartment in Chicago noted the following:
There may be one other barrier between residents and their views: the orb-shaped web of Larinioides sclopetarius, the high-rise spider.
''It's a species that's attracted to rocks overhanging water,'' said Dr. Petra Sierwald, a curator at the Field Museum here. ''These high-rise buildings are just very big rocks overhanging water.''
High-rise spiders can climb or balloon to the top on strands of silk blossoming from their spinnerets. They are clever enough to hide before the window washers arrive and plucky enough to spin a new web after the crew moves on.
''These critters eat like kings,'' Dr. Sierwald said. ''It's prime real estate for spiders.'' Entire article
Perhaps, the "Chicago Phenomenon" was the inspiration for Spider Man, and while most have never heard about this it seems there is nothing new or rare about Flying Spiders. Long ago sailors have reported spiders being caught in their ship’s sails. The spiders have also been detected in atmospheric data balloons. Apparently, flying or ballooning is the normal process where a spider shoots off long, silken thread so that the wind can carry them away to a different and/or distant location. Sometimes, the spiders are migrating to a different climate or habitat. Other times they are looking for a new food source. And sometimes, they're just looking for a mate.