The functional significance of cemented nest caps of the harvester ant, Pogonomyrmex maricopa

Harvester ants, Pogonomyrmex maricopa, construct cemented caps on the sand mound nests in a fine sand dune area. The caps are approximately 60% calcium carbonate that is transported from the underlying calcium carbonate layers. The caps protect the nest structure from being eroded away during high-wind periods. Partial erosion of the cemented caps adds calcium carbonate to the sand dune soils.