As a youngster I used to love lying on my back on our porch in the sunny summer days and watching the spiders ballooning. Sometimes the whole sky would just be filled with them, hundreds of feet up - you could only see them by the tiny glints when the sunlight hit the webs just right.
I haven’t seen them so numerous in a long time though. Maybe that was just a really good spot, or maybe I’ve forgotten to look enough.
Here’s what it looks like, for the curious: https://www.youtube.com/watch?v=iOtw8oMLf8A