Western Harvester Ant

Workers harvest seeds and pollen directly from plants and gather fallen seeds. Some seeds are sometimes stored in chambers within the nest and are depleted during winter. Workers also gather newly dead insects. Workers generally forage April–September. Workers generally forage throughout the day during cooler months and only 5–11 am and 3–9 pm during the summer. Genetically diverse colonies forage for more hours daily. Foraging times within a day and foraging temperature range vary consistently among colonies. Given a choice, workers select seeds containing more energy. Given a choice, workers select a diversity of seeds or seeds that are new to the colony. Workers usually forage one kind of item each day, but change their specialty daily. Workers usually forage in one direction over and over, even across days. Colonies recruit more workers (from the total worker pool) to forage at a good food source. Colonies lose foragers in encounters with neighboring colonies. Workers defend foraging territories against neighboring colonies. Different plant environments support different densities of colonies. Foragers produce more period mRNA during darkness, the timing of which varies seasonally.