Spider Rain Is RealYou may have seen videos of this shocking event, but it actually HAPPENS ALL THE TIME! Spiders climb to great heights and shoot themselves great distances on a stream of silk and land far away in a process called ballooning. We just don't notice when a single spider does it. Scientists believe the 'spider rain' events occur when bad weather causes hundreds of thousands of spiders to wait -- then they all go at once, creating a horrifying storm.