You see, back in the age of the mighty civilization of the dinosaurs, they had begun experimenting with genetic engineering.  One of their earlier attempts was to introduce glow-in-the-dark leaves on trees.  This provided illumination at night, and was quite picturesque.  These trees survived the dinosaurs that created them; but not by much.  The moths quickly evolved to recognize that light meant food, and ultimately they ravaged and completely destroyed all of the light-trees.  All that remains of that glorious time is the odd habit of moths to fly toward the light.