Spiders fly all the time, which is why a black widow popped out of a bunch of bananas last weekend in the grocery store my friend works at. Uh, those aren't from Chicago. Also, it's been below freezing for a long while and the spider would be a popsicle if it hadn't flown in from out of the country. On the upside, someone else I know got an anole with a house plant purchased from a hardware store. FREE LIZARD! He's living in a tank now.