A Collective of Pixies
A pixie's gotta do what a pixie's gotta do, and one of the things a pixie has to do is dance. It has to be done, so that the flowers will grow and fruit, the grass will do its photosynthesis thing, the trees will put down their roots properly and other processes will proceed in their proper time, at their proper pace.The pressure of the pixies' energetic little etheric feet may even be what helps to keep the world turning at the right speed - at least they claim it does. I know that physicists claim differently, but who wuld you rather believe? Besides, physicists keep changing their minds about things, and pixies have done this dance forever and the world has kept on turning hasn't it? All the physicists do, anyway, is to explain how the pixies' dance works, not who does it.
From Brian Froud's Good Faeries Bad Faeries and The Faeries Oracle