How do I know what kind of ant I have?

Quick Ways to Identify Ants

Ants are one of the most common insects found in homes and yards. There are over 12,000 known species of ants in the world, with around 700 species found in the United States alone. Identifying the type of ant you have can be useful for controlling infestations and understanding their behaviors. Here are some quick ways to identify the most common household and yard ants:

Look at their color – Reddish ants like fire ants and harvester ants are aggressive. Black ants like carpenter ants can damage wood.
Examine the size – Large ants like carpenter ants get up to 1/2 inch long. Tiny ants like pharaoh ants are only 1/16 inch.

Watch where they go – Sugar-loving ants like argentine ants go for sweet things in the kitchen. Grease-eating ants like crazy ants swarm pet food containers.
Note if they sting – Fire ants and harvester ants have a powerful, painful sting. Odorous house ants spray a foul smelling chemical.
See if they build hills – Ant colonies that build dirt mounds outside like fire ants and harvester ants can have hundreds of thousands of workers inside.

If you can safely catch one, looking at details like the color, number of body segments, size of the head, and presence of wings can help pinpoint the species. An exterminator can also help identify infestations if the ants are inside your home. Accurately identifying the ant allows you to find the best control methods.

Detailed Ways to Identify Common House and Yard Ants

More detailed identification of ants involves looking closely at their physical characteristics and nesting habits. Here are tips for identifying some of the most common ant species:

Argentine Ants

Appearance: Light to dark brown in color, 2-3 mm long

Food preference: Sweet substances like honeydew from aphids and sugary foods in the kitchen
Nesting habits: Outdoors in moist soil and thatch, or indoors in wall voids and insulation
Behavior: Aggressive invaders that attack other ant colonies and food sources

Origin: Native to South America, now found worldwide

Argentine ants are one of the most common small ant invaders. They trail along the edges of kitchen counters and floors in search of sweets. Outdoors they farm aphids and scale insects for honeydew. They do not sting but will aggressively attack other insects and ants.

Carpenter Ants

Appearance: Large black ants 12-25 mm long with evenly rounded thorax

Food preference: Sweets such as tree sap, nectar, honeydew, and protein from dead insects
Nesting habits: Hollowed out galleries in wood consisting of satellite nests from one central colony
Behavior: Nocturnal and shy, coming out at night to forage

Origin: Native species found worldwide

Carpenter ants tunnel into wood to create nest galleries. They can cause severe structural damage if left unchecked. Foraging worker ants are timid around people but can give a painful bite. Swarms of reproductive winged ants emerging indoors indicates an established nest.

Crazy Ants

Appearance: Dark brown to black color, long antenna, erratic and fast movement

Food preference: Omnivorous but prefer high protein from living and dead insects, pet food
Nesting habits: Under rocks, landscape material, mulch, etc. with multiple interconnected nests
Behavior: Fast moving and ‘crazy’ movements, can be aggressive invaders that swarm

Origin: South America and the Caribbean

Crazy ants earned their name from their quick erratic movements and ability to suddenly swarm in high numbers. They do not sting but can bite and can be a nuisance pest. They prefer moist environments outdoors and will forage indoors for protein sources.

Fire Ants

Appearance: Light brown to black color, 3-6 mm long, head and abdomen are of different sizes

Food preference: Protein and fatty foods like insects, eggs, seeds, etc.
Nesting habits: Large rounded mounds of excavated dirt pellets up to 2 feet high
Behavior: Aggressive biters with a painful venomous sting, swarm quickly when nest is disturbed

Origin: South America, now found throughout southern coastal U.S.

Fire ants are very aggressive and swarm out of their mound nests quickly when disturbed. They have a painful sting that leaves itchy blisters. Their mounds in lawns or fields have no visible entry hole. They forage during the day in a wide area around the nest.

Harvester Ants

Appearance: Red and black colored large ants 12-15 mm long

Food preference: Seeds, dead insects, sap, honeydew, etc.
Nesting habits: Deep underground nests with large cleared entrances and excavated soil
Behavior: Slow moving foragers that can inflict a painful sting

Origin: Western North America

Harvester ants slowly forage alone on open ground and vegetation. Their large piles of excavated soil have a cleared entrance hole. Aggressive defenders near the nest entrance can inflict a painful sting. They play an important role in seed dispersal.

Odorous House Ants

Appearance: Medium sized black ant 2-5 mm long with uneven abdomen

Food preference: Sweet and protein foods like nectar, honeydew, insects
Nesting habits: Rotting wood or soil outdoors, in insulation/wall voids indoors
Behavior: Give off a strong foul odor when crushed or disturbed

Origin: Native to North America

Odorous house ants do not sting but release a rotten coconut-like smell when disturbed as a defense. They forage at night on sweets, proteins, and greasy or spicy human foods indoors. Nests have multiple queens with satellite nests interconnected by foraging trails.

Pavement Ants

Appearance: Black or reddish brown ants 2-5 mm long

Food preference: Sweet foods high in carbohydrates, especially honeydew and nectar
Nesting habits: Under stones, pavement, soil, indoors in wall voids and insulation
Behavior: Non aggressive foragers that travel along edges

Origin: Native to Europe, imported to North America

Pavement ants build nests under pavement, stones, and in buildings, usually next to heat sources. They trail along the edges of walls and floors, foraging day and night for sweets. They do not sting or bite.

Pharaoh Ants

Appearance: Very small yellow or light brown ants 1-2 mm long

Food preference: High protein and greasy foods
Nesting habits: Indoors in warm hidden spaces near heat sources and plumbing
Behavior: Do not sting or bite but can be a nuisance pest

Origin: Believed to originate from tropical Africa

Tiny pharaoh ants forage in long trails on counters, floors, and walls indoors searching for protein sources. They prefer warm humid conditions and do best where temperatures stay above 80°F. Used moistened cotton balls placed along foraging trails can help locate nests.

Identifying Ants by What They Are Doing

Looking at ant behavior and food preferences is another way to identify different species:

Following sweet trails – Argentine ants, crazy ants, pavement ants
Swarming around proteins – Crazy ants, fire ants, pharaoh ants
Carrying off greasy or meaty bits of food – Fire ants, pharaoh ants, thief ants

Climbing up trees – Carpenter ants foraging at night
Circling kitchen sinks and drains – Odorous house ants seeking water
Nesting in the ground outdoors – Harvester ants, fire ants

Attacking other insects – Argentine ants, fire ants
Ignoring nearby food baits – Ghost ants do not eat sweets or oils

Watching where the ants go and what food they take can provide clues to identify the species before they disappear back into hiding. Place a bit of sweet food like jelly as well as some greasy meat or nuts near ant trails to see which they prefer.

Winged Ants and Swarmers

Seeing winged ants emerge indoors is a sign of a mature nest that is big enough to produce reproductive swarmers. Some signs a swarm is imminent or happening:

Carpenter ants – Large black winged ants near lights at night
Odorous house ants – Groups of winged ants gather near windows and doors

Argentine ants – Hundreds of tiny winged ants covering windows, walls, counters
Pharaoh ants- Clusters of small winged ants seen near heat sources and plumbing

Swarming is the main reproduction method for ants. After mating, the winged ants will shed their wings and try to start a new nest or colony. Finding and treating indoor nests after swarming ends can help prevent future infestations.

Conclusion

Identifying the species of ant you are dealing with is an important first step in controlling infestations and getting rid of them. Quick identification can be made by looking at color, size, food preferences, nest locations, and behavior. Trailing and swarming ants indoors indicates an active nest that should be treated. Correct identification allows you to find the nest location and use baits and treatments that target that particular species for maximum effectiveness. Understanding the ant’s food preferences and foraging behavior also helps you locate and eliminate nesting sites.

Ant Identification Chart

Ant Type	Appearance	Food	Nest Site	Behavior
Argentine Ant	Light to dark brown, 2-3 mm	Sweets like honeydew	Soil, thatch, voids	Invade in trails, attack others
Carpenter Ant	Large black, 12-25 mm	Sweets, insects, sap	Hollowed wood galleries	Nocturnal, shy, can bite
Crazy Ant	Dark brown to black, erratic	Proteins, pet food	Under objects, mulch	Fast moving, swarm quickly
Fire Ant	Light to dark brown, 3-6 mm	Proteins, fats	Dirt mounds, up to 2 ft high	Aggressive sting, rush out of mound
Harvester Ant	Red and black, 12-15 mm	Seeds, insects, sap	Deep underground nests	Slow moving, painful sting
Odorous House Ant	Black, uneven abdomen, 2-5 mm	Sweets, proteins	Rotting wood, voids	Release foul odor when crushed
Pavement Ant	Black or brown, 2-5 mm	Sweets like honeydew	Under stones, voids	Non-aggressive trails along edges
Pharaoh Ant	Yellow or light brown, 1-2 mm	Proteins, grease	Hidden voids near heat	Do not bite or sting

Tips for Identifying Ants

Look at color, size, body shape
Note food preferences and trail locations

Watch behavior – do they swarm, bite, sting, move slowly?
Find nest location – mounds, under objects, in wood?
Catch one safely to examine details like wings and antennae segments

Pay attention to swarmers emerging as a clue to indoor nest sites
Use identification guides and expert help for difficult to identify species

Correct identification allows you to find the nest and choose effective baits and treatments to control that particular ant species. Understanding their foraging behaviors also helps you locate and destroy nests. Eliminating ants at the source is key to getting rid of ant trails and keeping them from invading your home.

Frequently Asked Questions

What are the most common ants found indoors?

The most common ants that become home invaders include pharaoh ants, crazy ants, pavement ants, argentine ants, odorous house ants, and carpenter ants. Tiny sugar loving ants follow trails into kitchens from outdoor nests. Carpenter ants nest in wood but come inside walls for food.

What do I do if I can’t identify the ant species?

Catch a sample ant in a sealed container if you can safely do so. Take detailed photos of the ants and send them to your local extension office or exterminator. Describe when and where they are found, trails, food interest, and other behaviors to aid identification. Misidentifying ants leads to ineffective treatments.

Why do I suddenly have swarms of flying ants in my home?

Seeing clusters of winged ants swarming indoors is a sign that a nest has matured enough to produce reproductives. Swarming happens seasonally with some species like carpenter ants. Finding where they emerge from helps pinpoint hidden nest locations in voids and wood that need treatment.

Are there any benefits to having ants around?

Some ant species help control pests by preying on insects like termites. Ants aerate soil and disperse seeds outdoors. But ants that invade become nuisance pests. Enjoy observing outdoor ants, but avoiddamage and stings by treating infestations.

When should I call an exterminator to identify ant species?

If you are unable to identify ants that are invading your home or stinging family members, call a professional. Extensive indoor trailings, multiple nest locations, mushrooms sprouting indoors, or extensive structural damage also indicate a major infestation needing professional treatment.