I agree CM. This to me seems to be a good attempt to recreate medieval 'scholarly' texts and to me he seems to be discussing the origins of fire in general, in much the same vein as frogs appear spontaneously from mud.
Good! For me these things make me overthink - how do such creatures come about? Did they recently adapt to draw energy from magic? If not, what did they use before intelligent races evolved and developed magic?
Where they the creation of some asshole god, or a wizard who wanted bugs to seek out magic items?