Ants - General
Overview
Ants are very numerous and are one of the most successful insects. They are social insects and live in colonies which are located in: (1) Soil, refered to as "soil dwelling ants" (make mounds in the yard) and (2) Structures, refered to as "structure dwelling ants" (nest in structures, trees etc.). Ants will have either 1 or 2 pedicel nodes which helps in identifying them (the pedicel is the "thin" segment which connects the abdomin to the thorax). The biology and habits of each ant species are different so the following is a general description of the ant species which can be pests in our area.
Ants:
- Vary in color, red, black, brown, yellow or combinations of these colors.
- Have a complete life cycle: Egg → Larva → Pupa → Adult. There are no “baby” ants. They have 3 distinct castes: Queen, Workers and Males.
- Workers are females, never with wings. They can be 3 sizes: minor, media and major. They do all the work of the colony: gather food, care for the young and enlargement and protection of the nest.
- Males exist solely to inseminate the queen and will usually die within 2 weeks of mating.
- Queens, which are usually the largest ants in the colony, function to establish new colonies and lay eggs.
- For most species of ants, the colony will contain many functional females or queens, but only 1 founding Queen.
- Generally, un-mated functional females have wings; mated females will chew them off after finding a suitable site for a new colony.
- Many species start new colonies by a process called “Swarming;” winged females and males (called Winged Reproductives) fly off and mate, usually in late spring/early summer. Some species do not swarm, but go through a process known as “Budding;” in which a group of workers will take some larvae and pupae and go off to a suitable location and start a new colony.
TWO NODE ANTS
PAVEMENT ANTS Soil Dwelling
# of Node Segments: Two
# of Sizes of Workers: One
Size of Workers: 3/16 inch
Shape of Thorax: Uneven
# of Antenna Segments: 12
Antennal Club: 3-segmented club
# of Pairs of Spines on Thorax: One
Color: Dark brown
Other ID tips: Grooves are present on head and thorax. Stinger present at tip of abdomen. Commonly encountered under slab foundations (townhouses etc.), sidewalks, patios etc.
PHARAOH ANTS Structure Dwelling
# of Node Segments: Two
# of Sizes of Workers: One
Size of Workers: 1/16 inch
Shape of Thorax: Uneven
# of Antenna Segments: 12
Antennal Club: 3-segmented club
# of Pairs of Spines on Thorax: None
Color: Yellow with reddish abdomen
Other ID tips: Cannot survive outdoors in Minnesota. Nest in moist areas, close to food and water. Nests can be very large. Stinger present at tip of abdomen. Will feed on open flesh and can spread disease.
THIEF ANTS
# of Node Segments: Two
# of Sizes of Workers: One
Size of Workers: Tiny 1/32 inch
Shape of Thorax: Uneven
# of Antenna Segments: 10
Antennal Club: 2-segmented club
# of Pairs of Spines on Thorax: None
Color: Yellow
Other ID tips: Stinger present but very small, Prefer food with high protein. Often confused with Pharaoh ants (key difference is the antennal club). Will sometimes nest near or in the nests of other ants.
ONE NODE ANTS
CARPENTER ANTS Structure Dwelling
# of Node Segments: One
# of Sizes of Workers: Many
Size of Workers: 1/8 to 5/8 inch
Shape of Thorax: Evenly rounded, lacks spines
# of Antenna Segments: 12
Antennal Club: None
Tip of Abdomen: Has circle of hairs, no stinger
Color: Varies with species; black, brown, red, red/black
Other ID tips: Do not go by size or color. Look for evenly rounded thorax, and circle of hairs at tip of abdomen. Often confused with Field Ants
FIELD ANTS Soil Dwelling
# of Node Segments: One
# of Sizes of Workers: Many
Size of Workers: 1/8 to 3/8 inch
Shape of Thorax: Not evenly rounded, no spines
# of Antenna Segments: 12
Antennal Club: None
Tip of Abdomen: Has circle of hairs, no stinger
Color: Brown, Black, Reddish or combination
Other ID tips: Make very large mounds outdoors. Often confused with Carpenter Ants
CORNFIELD ANTS
# of Node Segments: One
# of Sizes of Workers: One
Size of Workers: 1/8 to 1/4 inch
Shape of Thorax: Uneven, lacks spines
# of Antenna Segments: 12
Antennal Club: None
Tip of Abdomen: Has circle of hairs, no stinger
Color: Brown to very dark brown
Other ID tips: Eyes large, no ocelli (simple eyes) present on top of head. Inside, they are associated with a preexisting moisture problem.
YELLOW ANTS
# of Node Segments: One
# of Sizes of Workers: Many
Size of Workers: 1/4 inch
Shape of Thorax: Uneven, lacks spines
# of Antenna Segments: 12
Antennal Club: Gradually enlarges to tip
Tip of Abdomen: Has circle of hairs, no stinger
Color: Yellow-orange
Other ID tips: Workers give off citronella or lemon odor when crushed. Nest in soil outside, or in damp, moist, rotted wood inside
ODOROUS HOUSE ANTS
# of Node Segments: One
# of Sizes of Workers: One
Size of Workers: 1/8 inch
Shape of Thorax: Uneven
# of Antenna Segments: 12
Antennal Club: None
Tip of Abdomen: No circle of hairs, no stinger
Color: Brown to black
Other ID tips: Node is hidden by abdomen. Workers give off a rotten coconut smell when crushed. When disturbed the workers will erratically run around with their abdomens raised up. Multiple queens
There are many, many more species of ants, but these are perhaps the most common in our area.
CONTROL
The basic treatment procedure would consist of an application of a non-repellent material to provide a residual barrier mainly on the exterior, but also in selected interior perimeter areas. We recommend that this service be done twice per year - Sping and Fall, thereby giving year 'round control. Control methods may vary slightly with the difference species.
