Old Enemies

Despite common belief dragons despise butterflies. I am not quite sure why, though I have a theory.
Butterflies are beautiful and colourful, they are the treasures of the animal kingdom. However they are also alive, making them difficult to catch and they have a general unwillingness to lie down and become a permanent fixture in a pile of treasure. Should they be caught they also disintegrate in heat and with rough handling.
Thus Butterflies are an unending source of frustration to dragons. They covet butterflies yet ultimately destroy the treasure they long to poses. It is probably then, in their frustration that they burn to dust the entire field of flowers the butterfly once called home and return to their cave to curl up on some less rebellious treasures.