Sandworms are attracted to rhythmic vibrations in the sand, which they mistake for prey (smaller sandworms). To escape the notice of the sandworms, a traveller in the desert must learn to "walk without rhythm" in a manner that simulates the natural sounds of the desert. This element comes from Frank Herbert's experiences as a hunter and fisherman. He knew how to mask his presence from prey by techniques such as approaching from downwind and treading lightly. Frank Herbert's son Brian explained that "In Children of Dune, Leto II allowed sandtrout to attach themselves to his body, and this was based in part upon my father’s own experiences as a boy growing up in Washington state, when he rolled up his trousers and waded into a stream or lake, permitting leeches to attach themselves to his legs."
