Identifying the 7 Most Common Ants in the US

Rarely do we spot a lone ant marching unaccompanied by an entire horde of them. Ants grossly outnumber us, and they are just about everywhere. While there are over 700 types of ant species in the world, just a few are known to be in and around homes. Knowing how to identify the type of invading ant in your home is a vital first step in trying to control them.

FIRE ANTS

Measuring at lengths between ⅛ to ⅜ of an inch, these invasive ants can be identified by their reddish color, visible stingers, and large communities. Their colonies can reach up to 500,000 ants, which means bad news for anyone unlucky enough to stumble upon a nest. Should you come upon a large, dry mound measuring 2-4 feet in width with a flattened, irregular shape, steer clear.

Fire ants earned their name not for their color, but for their painful stings. These ants are highly territorial and will strike if they feel threatened. And due to the large size of their colonies, any accidental intrusion into their nest may result in stings from more than a few angry pests. Baiting for these aggressive insects is a simple process that a professional pest control expert can take care of for you.


ODOROUS HOUSE ANTS

These ants emit a coconut smell when stepped on. Ranging from dark brown to black, odorous house worker ants are very small—between 1/16 to ⅛ inch long—and have a distinctly irregular thorax. Their nests are shallow, often under stones, wood, or other debris. Because odorous house ants don’t require large nests, they, as their name implies, invade homes and nest near pipes, heaters, and in wall voids.

Odorous house ants get their nickname of “sugar ants” because of their affinity for sweets. Outdoors, they feed on nectars and plant sugars, as well as small, herbivorous bugs such as aphids. Indoors, these ants prefer to forage for any drops, spills, or other sources of food containing sugar or its derivatives. Controlling these ants is best done through exclusion methods, and baiting these ants must be done with sweet bait such as boric acid that workers will bring back to the colony for others to consume as well.

ARGENTINE ANTS

Argentine ants are not only common, but also prolific and very prolific—millions of ants can make up a single colony. Colonies nest underground in the soil, with small, 1-2 inch mounds found above the surface in undisturbed, open areas. These ants are small, just ⅛ inch, and uniformly brown, traveling in distinct trails along sidewalks, up buildings or trees, and even underneath carpet edges.

Argentine ants forage for sweets and other scraps, often feasting on plant buds and sweet secretions from small, plant-friendly insects. These ants are also known to forage for crumbs and oils indoors, so sealing off all points of entry for these tiny insects is crucial to preventing an infestation. Sweet baits or traps should be placed outside rather than in, as indoor use could have the unintended effect of attracting more Argentine ants inside.

PHARAOH ANTS

These ants are an imported species most likely originating from Africa. They’re easily identifiable by their golden bodies and small size, with an average length of 1/16 of an inch. Pharaoh ants are often found indoors, especially in the winter months, and seek places with adequate warmth and moisture. They tend to nest in indoor structures such as behind baseboards, within walls and cabinets, inside insulation, and behind curtains and stacks. When nesting outside, the ants are often drawn to cracks and crevices which will provide the damp warmth they prefer.

Like many other ants, pharaoh ants like a diet of sweets, but they also snack on insects (both living and dead) and forage for food sources rich in fat. Because a pharaoh ant infestation happens primarily indoors, bait that includes both fat and sweet materials must be placed around the house near places they’re likely to be nesting—in corners and cabinets, near pipes, around windows, and by any other potential source of moisture.

THIEF ANTS

Worker ants of this type are incredibly small at only 1/32 of an inch. Thief ants can be spotted by their yellow or light brown bodies and segmented antennae. Their colonies are small and scattered, and their nests are shallow, often under rocks and wood outside and behind baseboards and in cabinets inside. These ants earned their name through their behavior; they travel to other ant colonies and steal the pupae and larvae of other populations.

Thief ants thrive on a diet of protein and fats and can be found foraging for fatty foods and even feasting on dead insects and rodents. Because of this, a thief ant colony’s presence poses an elevated risk. Bacteria and pathogens from the dead rodents, insects, and other rotten food they’ve eaten can easily be transported along the defined trails thief ants travel. Exclusion methods are most effective at keeping these ants out, but bait that has fatty or protein-based material can also be placed near potential nest sites or entry points for good measure.

PAVEMENT ANTS

Pavement ants get their name through their habitat: on and beneath sidewalks and pavement. These dark brown to black ants are a hallmark of suburbia and can be spotted just about anywhere there is a walkway, driveway, paved path, or building foundation. Their workers are all the same size, and average at just under 1/4 of an inch. Their nests are dirt mounds near or underneath pavement and stones.

These ants feed on fruit, sweets, greasy food, meat, pet food, dead insects, and various garbage scraps. Controlling these ants and keeping them from taking over indoor spaces can best be done through sealing cracks, gaps, and other holes that allow them entry into your home. Also be sure to clean up any messes or spills so that these accidents don’t become unintentional ant attractants. A pest professional will either locate and treat the nest or use baits to get rid of these ants.

CARPENTER ANTS

Reddish black, large, and found most often nesting in wood, a carpenter ant infestation can bring real structural damage with it. Unlike termites, carpenter ants do not eat wood. Instead, the damage brought on by these insects is due to workers burrowing into structures, trees, furniture, and other wooden materials in order to accommodate the thousands of ants in each colony. Nests indoors may be smaller sites dependent upon a larger nest found outside in trees, logs, or landscaping, especially in areas that are rotting or moist.

Carpenter ants can make their way indoors foraging for food, and with a diet open to fats, proteins, insects, meat, herbivorous insect secretions, and sweets, they’re bound to find something they’ll enjoy. Because they can cause troublesome structural damage, these ants are best controlled by employing exclusion methods to seal them out and by eliminating attractive nesting sites by cleaning up moisture, making repairs to structures, and cutting off any vines, branches, or bushes that act as bridges to your home. Baits can be used to find potential colonies and locate nests for treatment.

Ants generally have a sweet tooth, but baiting and locating their nests is not a one-size-fits-all process. While most ants can be deterred by removing standing water, ensuring your home is clean, and practicing proper exclusion techniques, the differences in ants’ diets and nesting preferences will determine how to treat an infestation. Tackling any ant invasion can be a huge project. For support in identifying the ants at your door, locating nests, and building a treatment plan, feel free to give us a call. Keeping your home protected from pest intruders is our main objective, and we’re always prepared to lend a helping hand!

SOURCES

http://ipm.ucanr.edu/m/pn7411-3.html
https://extension2.missouri.edu/g7392
https://extension.umn.edu/insects-infest-homes/ants
https://www.pestworld.org/pest-guide/ants/
http://ipm.ucanr.edu/TOOLS/ANTKEY/odorbait.html
http://ipm.ucanr.edu/PMG/PESTNOTES/pn7411.html
https://extension.umn.edu/insects-infest-homes/ants#pharaoh-ants-42363
https://cisr.ucr.edu/invasive-species/argentine-ant
http://ipm.ucanr.edu/TOOLS/ANTKEY/pharaoh.html
http://ipm.ucanr.edu/TOOLS/ANTKEY/thief.html
http://ipm.ucanr.edu/TOOLS/ANTKEY/pavement.html
http://ipm.ucanr.edu/PMG/PESTNOTES/pn7416.html