Harvester ants are a group of ants known for collecting, or “harvesting,” seeds. This activity gives them their common name, as seeds are their primary food source. These insects play a role in their ecosystems by storing plant seeds for their colonies.
Global Distribution
Harvester ants are found across several continents, inhabiting diverse regions. They are prevalent in North America, particularly in drier, warmer areas of the United States, Canada, and Mexico. They are also found in parts of Africa, Europe, and Asia. These ants typically thrive in arid and semi-arid climate zones, reflecting their adaptation to environments where seeds are readily available.
Preferred Habitats and Environments
Harvester ants flourish in specific natural settings that support their seed-collecting. They are found in open, dry environments like deserts, grasslands, prairies, and open woodlands. They also establish colonies in disturbed open areas, including plains, lawns, and playgrounds. They prefer warm, dry, exposed sandy soils, though some species adapt to soils with higher clay content.
Vegetation in their preferred habitats typically ranges from sparse to moderate, allowing efficient foraging. Harvester ants often clear vegetation around nest entrances, creating bare patches that prevent shading and facilitate activities. Optimal temperatures for many species range between 24°C and 28°C (75°F to 82°F), and they forage effectively in hot, dry conditions. Metabolizing fats from seeds helps them obtain water in these warm, dry environments.
Nesting Structures and Colonies
Harvester ant colonies create complex underground structures. Their nests are typically subterranean, featuring extensive networks of tunnels and chambers that can reach significant depths, often up to 2.5 meters or even deeper, sometimes extending to 4.5 meters (15 feet). The surface expression of these nests often includes characteristic mounds, which can be flat and broad, occasionally reaching up to 1 meter high and 5 meters in diameter.
A notable feature of a harvester ant nest is the cleared area surrounding the entrance, which can be circular and vary in size from 2 to 10 meters in diameter. This bare patch is maintained by the ants to prevent shading and regulate temperature. Within the underground chambers, harvester ants store collected seeds in communal areas known as granaries, ensuring a stable food supply for the colony.