Pavement Ant Mound
Harvester ants gather seeds and other foods and store them in underground nests. The ants feed on the seeds, process the food and deposit waste in and around the nest area. Ant activity can have a profound impact on soil chemistry and biota. Collecting seeds from adjacent areas removes nutrients such as nitrates and phosphorous and impoverishes soils nutritionally. Depositing seeds in the nest enriches the soil for nitrates and phosphorous.
Over time, soil of the ant mound…
Source: Living With Insects Blog