So what is the behaviour of this stuff? How does it come together to form "patches"? If it really agglomerates naturally into (admittedly, very big) clusters th

So what is the behaviour of this stuff? How does it come together to form "patches"? If it really agglomerates naturally into (admittedly, very big) clusters this actually sounds kind of like good news, as it seems more viable to come up with a way to clean it. But I'm curious what the mechanism is. Static electricity? Sounds too distant and "wet" for that to be possible. But why else would it cluster?