Fossorial animals use different strategies to move under ground; burrowing and piling up soil above ground, or pounding their way through soil by compaction. Subterranean termites, however, neither pile up soil nor move sand to build architectures above ground. Additionally, they are too weak to directly ram sand along tunnels. We hypothesize that termites move sand with their mouthpart from excavating sites to depositing sites and meantime deposit and compact the sand. Low density (high porespace) sand is transferred into high density (low porespace) sand by this process. Porespace between sand particles was concentrated to form hollow tunnels.