How do harvester ants primarily obtain their food?

Harvester ants primarily obtain their food by gathering seeds and plants, which classifies them as herbivores. These ants have developed a specialized foraging behavior where they actively collect seeds, especially from various types of grasses and other plants. This feeding strategy is crucial for their survival, as seeds provide essential nutrients and energy for the colony.

Harvester ants are known to cache the seeds they collect, storing them in their nests to ensure a constant food supply, especially during periods when fresh forage is scarce. This behavior not only supports their immediate dietary needs but also helps in the ecosystem, as they contribute to seed dispersal, aiding in plant reproduction.

The other options present alternative feeding strategies that are not typical for harvester ants. For example, scavenging on wood and hunting insects do not align with their dietary habits, nor do they consume decaying matter. Thus, the primary food source for harvester ants remains the gathering of seeds and plants, which is integral to their role in their environment.