Flow Cotton Fiber

And on the slide landed a peculiar dust speck. It LOOKED like a "fuzzy", just a single fiber to the naked eye, like maybe of cotton or something. It was just a little string. And it was blue. But as I looked at it NOT through the microscope, it was obvious that it was quite alive. It was moving around, squirming like a worm of some sort, even when I kept air flow from moving it around, it was moving around in a very characteristically wormlike way. If it wasn't a really lousy microscope I might have gotten a better view of it, but all I saw was a really thick blue rope that was moving around.

So what sort of creature do you suppose it was?
But it wasn't in my brain, it landed on the microscope slide. Kind of creepy that it was just floating around in the air along with the normal dust though.