A mouse scurried through the air, for it was made of cheese. That is, the air was, not the mouse.
In fact, all of Canterlot was currently a massive, cheesy brick of... cheese.
Not much could be said about how it happened, or in fact, why, but there had been a rumor that mentioned that it may have been the doing of Celestia after she drunkenly dreamt of Gouda dreams.
Nopony really noticed, or really cared, for that matter. The orphans of Canterlot happily chewed their way through the cheese, and some even found their parents in the very tunnels they had eaten out.