Ants are social insects that live in colonies that can have one or more queens. An average sized colony houses around 4,000 ants. Ants can colonize underground, in leaf clutter or inside a structure. They have a 3-part segmented body: head, thorax, and gaster. Reproductive ants have wings. Ants can carry 20 times their body weight and live on average 45–60 days.
Characteristics: Carpenter ants are relatively large. Known mostly by size and color, carpenter ants are commonly black; however, their color can range from black to red or even solid red. Carpenter ants have one segment to their waist and a long abdomen containing lightly-colored dull hairs. Though the name suggests otherwise, carpenter ants do not eat wood. They feed on plant juices and other insects. Black carpenter ants do bite and can spray formic acid, but they do not possess the ability to sting their prey.
Habits: Most carpenter ant species establish their first nest in decayed wood and later expand into sound wood. Within structures, nests are located in wood (preferably softened by fungus rot or water damage), in insulation and/or wall voids. Worker carpenter ants are a nuisance when out searching for food and are destructive to timbers utilized for nesting activities. Outside structures, nests are typically found in rotting fence posts, stumps, old firewood, dead portions of standing trees and under stones or fallen logs. Swarming carpenter ants can appear inside or outside homes and structures from spring to fall. Swarming black carpenter ants can easily be mistaken for swarming termites if inside homes and structures.
Characteristics: Field ants are large ants (3/8-inch) and are often confused with carpenter ants. Field ants vary widely in color and can be black, brown, tan, reddish, or red and black in color. Sometimes field ants are commonly called thatching ants because of their habit of constructing mound of thatch of plant material, often grass.
Habits: Field ants are common around structures, but are not often found inside. These ants are soil nesters and may construct mounds in open fields. In lawns, these nests have a low profile, rarely reaching above the top of the grass. Field Ants also nest under objects like rocks, landscape timbers and firewood piles. Displaced soil is often evident. Items such as stones, logs, and bricks should be overturned and inspected for colonies underneath. Field ants don’t normally invade homes. When they are found indoors it is because they are searching for sweets. Field ants primarily feed on honeydew from aphids, mealy-bugs, scale insects found on trees and shrubs.
ODOROUS HOUSE ANT
Characteristics: Small workers, around 1/16-inch to 1/8-inch (2-3 mm); dark brown to black. Bitter odor when crushed—said to smell like rotten coconuts.
Habits: Odorous house ants are the most common ant species that invade homes in Iowa and the central United States. These ants nest in a wide variety of places outdoors and inside. Odorous house ants commonly construct shallow nests in soil underneath objects, such as stones, patio blocks and debris. Inside, they prefer areas with ready moisture, such as around hot water pipes and heaters, but also will nest in crevices around sinks and cabinets. These ants forage when temperatures are cool, even down to 50° Fahrenheit. Strongly trailing ants! Their trails can be found along foundations, flower beds, sidewalks and driveways. Odorous house ants prefer sweet items to feed on, but will also eat foods with high protein content and grease such as meats and cheese. In nature, they feed on honeydew from aphids.
Characteristics: Acrobat ants are very small, about 5.4 millimeters in length or less. They like to nest in moist areas and often can be found nesting behind siding, near a leaking roof, under rocks and in stumps or wood piles. Acrobat ants also like to nest in damage and galleries made by other insects. They like to eat sweets and meat and may emit an unpleasant odor when disturbed.
Characteristics: Pavement ants are 2.5 to 3 millimeters long and are light brown to black in color. Their appendages are lighter in color than the rest of their bodies, and have parallel lines on their head and thorax. They feed on a variety of foods, including other insects (dead or alive meats). Pavement ants establish trails from their colony to the food source and often infest kitchens, patios, and other similar areas. They often nest beneath rocks, concrete, and in walls and floors.
Characteristics: Pharaoh ants are tiny, approximately 2 millimeters long. They are yellow bodied with black and red markings on their abdomen. Pharaoh ants will typically nest in hidden, well-protected areas such as walls, voids, behind baseboards, in insulation and other warm areas inside a building. They prefer sweet foods but will also eat other insects. Pharaoh ants can spread disease and cause contamination.