Size: |
Harvester ant workers are about 1/4-1/2 in (4.7-11.5
mm) long. |
Color: |
Orange to reddish to dark brown or brownish black; some species
with two colors. |
Geographic Range: |
West of the Mississippi River in the United States, except for the
Florida harvester ant, which is found in the eastern U.S. |
Habitat: |
Harvester ants build medium to large sized mounds. Western harvester
ant mounds may be 1-4 ft. across and 2-10 in. high. They remove all
plants around the mound, probably to prevent it from becoming shaded.
In fields, red harvester ants may clear an area up to 35 feet across.
The western harvester ant sometimes covers its mounds with little
pebbles, charcoal, or dead leaves to help keep the nests warm. Most
species move their nests from time to time, if they have been fighting
with other ants, or if the mound becomes shaded by a tall plant. |
Food: |
These ants eat seeds, but usually feed on one species until it is
gone and then start in on another kind. They also eat insects. They
stay in the nest during the hot part of the day. There are two patterns
of feeding behavior. California harvester ants leave the nest one
by one and go in all directions. Red harvester ants start out from
the nest on main routes on which they have left a scent; where these
routes stop they go forth individually. |
Biology: |
Some species are warlike and almost always fight when they run into
even their own species from other colonies. Other species do not fight.
Swarming occurs during the summer. There are both male and female
swarmers. Mating occurs outside the nest, after which the females
fly off to start new colonies. |
Invasion: |
Harvester ants do not invade structures, but they do build nests
in yards, stripping the vegetation. |
Damage: |
Harvester ants remove growing plants from around their nests, which
causes large bare spots in lawns and fields. They may kill animals
that disturb their nests. They also have a painful sting, which may
be a special problem for people with allergies. Some species have
a barbed stinger, like that of a bee, that separates from their bodies
when used. |
