The harvester ant gets its common name from its behavior of collecting seeds. There are 22 species of harvester ants found in the United States. The most common types of harvester ants are the California harvester ant, Florida harvester ant, red harvester ant, black harvester ant and the Western harvester ant. All are limited to west of the Mississippi River except the Florida harvester ant.
Harvester ant mounds are moderate to large in size depending on the species. Typically, large areas surrounding the mound are stripped of vegetation to prevent shading, as harvester ants usually remain within the nest during the hottest part of the day. Most harvester ant species will periodically move their nest in response to a change in microclimate caused by shading of overhead vegetation. For example, the Florida harvester ant will move its nest on average once every 234 days.
Swarming typically occurs during the summer season, specifically in the afternoon following a rainfall. Harvester ants collect seeds as their main food source, but they also feed on other insects.
Harvester ants do not invade structures, but they are still considered an urban pest because their nests are often located near homes or in yards.
In addition to posing property threats in urban settings, harvester ants are also known to sting when their nest is disturbed. Harvester ant stings can cause painful sores and possible allergic reactions in people. Some species have a stinger with reverse barbs, so it actually breaks off in the wound, like that of a honeybee.