 Why do the webfoots only wear skirts?
A gray, funnel-shaped cloud of dust stood off to his left. Weather control made cyclones and other climatic phenomena on earth practically non-existent. But then, how could a group of loosely spaced grains of sand possibly have a nervous system? These creatures were not only humanoid, but definitely human, although more slight of build than earth people. All were dressed from the waist down only, in a shimmering skirt that sparkled as they moved. But up to now the tube and the chain was the only evidence of an advanced technology, unless the ancient inscriptions in the stone wall of the pool, and the statues lining the wall were evidences.
 The Sand God burned everything, except for the skirts.
 Skirts are traditionally worn by prisoners. The webfoots on this planet are all criminals or descendants of criminals.  The people from the sixth planet only sent skirts, when it was communicated that the Sand God had burned everything else.  The Sand God burned everything, except for the skirts.  Skirts are the traditional dress for the webfoots culture.