Mind you, that cocoon of dried ordure seems to be a very special protection against microbes, mites and other threats to the vulnerable pupa. Dried dung of various sorts can be surprisingly sanitary; cattle dung, suitably prepared, is a component of earthen floors in various countries to this day, including India and parts of Africa. In South Africa even well-to-do, respectable Boer families lived on firm, odourless misvloere (literally "dung floors") till well into the 20th century. But don't get the wrong idea; you don't get a decent misvloer just by creating an indoor midden — it must be the right stuff in the right mix, properly prepared, and the result is to be swept, maintained, and respected. Damage the floor thoughtlessly and the lady of the house would be no better pleased than the owner of a modern wooden floor gouged by stiletto heels or the like.