Chigger fleas were windborne parasites of the desert. The term came from the Seven Cities (Bisbrha and Debrahl) language. They made use of Seven Cities' sandstorms, riding the winds in search of prey. In these conditions they were nearly invisible when seen head on, appearing only as a gray stain from the side. Those they bit were marked with red, swollen weals. Cedar-chip baths or the Escura plant were used to kill them.