Answer:
Inside a burning house, this thing is best to make. And best to make it quickly, before the fire's too much to take.
A house of wood in a hidden place. Built without nails or glue. High above the earthen ground. It holds pale gems of blue.
My life can be measured in hours. I serve by being devoured. Thin, I am quick. Fat, I am slow. Wind is my foe.
I have three hundred cattle, with a single nose cord
It's been around for millions of years, but is never more than a month old. What is it?
I have two eyes in the front and a lot of eyes on my tail