A Doomed Pilgrim in the Ruins of the Future

Lying face down, stiff as a board, and eating all the sand you can.

For some reason, I get the feeling that I should lie still on the ground and eat sand. I try to make sense of my strange instinct, to recall what half-remembered fact or notice what subconsciously-spotted detail prompts the thought. How would it be helpful to lie on the ground and eat sand? What makes it a better plan than simply turning and running?
Anyone but Chwoka should answer.