What are sod hut made of?

Sod huts, also known as sod houses, are primarily made of blocks of sod, which consist of grass and soil held together by the roots. These structures were commonly built by settlers on the Great Plains in North America, where timber was scarce. The thick layers of sod provided Excellent insulation against extreme temperatures. The roofs were often made of wooden beams covered with more sod or thatch for added protection.