From Winter Pasture, by 李娟 (Astra Publishing, 2021), Kindle pp. 23-24:
Inside the sheep pen, there was a layer of especially thick and hard manure. Cuma said that every month, it would rise by half a foot, and so it needed to be cleaned out several times over the course of the winter. The first cleaning, upon arrival, and the final cleaning, before departure, were the most important and most laborious. The first cleaning meant digging out a layer of mostly dry manure. The final cleaning happened during the warmth of spring, when a thick layer of soft, wet manure is dug up and spread around the sheep pen to dry for the following winter. Once dried, this manure is black and pure and just the right size. There is no better fuel for the winter.
The lowest layer of manure is close to the earth. Mixed with sand and soil, it becomes hard and clumpy. After a whole summer exposed to the sun and air, it can be dug up in slabs as straight as concrete. These manure slabs can’t be used as fuel, but they are the desert’s most important building material. The Chinese national anthem goes, “Use our flesh and blood to build a new Great Wall.” For the sheep, it’s “Use our poop to build a shelter from the wind and cold.” A sheep pen built from manure slabs is both neat and sturdy. What else could you use to build it with anyway? In the desert, there are no trees, soil, or rocks, only tufts of brittle grass jutting out of soft sand.
Even the place where we humans eat and live—our burrow—requires sheep manure. A burrow is a six-foot-deep pit. In the sandy desert, its four walls would easily collapse if not for the manure slabs. A few logs are laid on top of the manure-lined pit, some dry grass is spread on top, then smear some manure crumble on top of that and you have a “roof.” Finally, dig a sloping passage to enter the sealed cave. Of course, the passage walls must be tiled with manure slabs as well.
Even the wide platform on which we slept was built with manure slabs. Basically, we lived in sheep manure.
“Living in sheep manure” might sound unappealing, but in reality, it’s great. Not only is sheep manure the sole building material available in the desert, it is also incomparable—in the dead of winter, only animal feces can magically, continuously radiate heat. This was never more apparent to me than on the coldest nights when we herded the sheep into their pen. The northern winds howled. It was so cold, I could barely open my eyes and the pain was like I had just been punched in the face. But the very moment I came near the thick manure wall, the cold vanished and a feeling of warmth washed over me.