As it retreats, it collects with it a large numéro of other hexagons, who implode to create a solid tournant peigne . They do this using local rules, which allow them through much ignorance and persistence to create great structures which will at least last through the winter.
J'ai refermé le livre, j'ai quitté l'immeuble, et suis monté dans ma voiture pour le long voyage de retour.