(Top) Experimental setup (left) and map of creep strains within the sandpile measured via Diffusive Wave Spectroscopy (DWS) (right). At the moment of preparation and up to 11 days after pouring (right), spatially-heterogeneous creeping motions appear within the pile. (Bottom) Heat perturbations reset the creep rate and the timescale of relaxation (left) while tapping reduces the creep rate, and confines deformation to the free surface (right)