The most tragic creatures in the world?
They use the moon to navigate, and the angle of it keeps them going in a straight line. Its also always above the horizon.
But since man-made lighting has been around, it confuses them and so the fact its often below them or above them at strange angles makes them fly around in spirals.
I feel awfully sorry for them. We've basically screwed up their entire lives.
So in future, don't you dare ever kill a moth if its in your room. It didn't want to be there, the poor darling. It didn't invade you like a spider. It just followed bad signs and took a wrong turn.