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Ant Identification Guide With Photos

GreenMind publishes authoritative and detailed guides to the things you're curious about.

Ants are fascinating insects.

Ants are fascinating insects.

Ant Identification: What You Need to Know About Ants in Your Home and Garden

Ants are insects in the same order as wasps and bees (Hymenoptera). They typically lack wings and are smaller than the insects in those groups, but like bees and wasps, many ants can sting. Some species, such as the red imported fire ant, (RIFA) are serious pests that can drive down property values and launch serious, sometimes fatal attacks on people and pets.

This guide is a good place to start if you notice that ants are in your house or are congregating in your yard or garden. It's also a valuable primer on an insect group that is much more than just a bunch of pest species—some ants exhibit behavior so sophisticated that it defies belief, while others are both completely harmless and truly beautiful, especially under the microscope.

If you do identify an ant species that is problematic, your next step is likely to seek some method of control. Please bear in mind that chemical and toxic control methods have destructive outcomes far beyond the ants themselves, and in some cases cause more problems than they solve. If it's at all possible, begin with natural methods and escalate the battle to toxins only if all else fails.

Carpenter Ants

Carpenter Ants

Carpenter Ants: Genus Camponotus

Carpenter ants are large, black ants that you will sometimes see around your home, or outside in areas where there are trees. Despite their size—sometimes approaching an inch in length—carpenter ants are harmless and do not sting people. However, these ants can sometimes pose a threat to buildings.

Carpenter ants build nests inside damp or rotting wood. They use their big mouthparts (mandibles) to chew up and remove the weak wood and construct galleries in which they raise their young. Carpenter ants do not eat the wood they remove, unlike termites (termites are insects that resemble small pale ants; they actually consume wood, and can literally eat your house out from under you). Carpenter ants can damage wood, but they are unlikely to destroy your house the way termites can.

Another way in which carpenter ants can pose problems is with their tendency to build their nests in aging, damaged, or diseased trees. A tree weakened by carpenter ants may be more likely to fall, causing damage to cars, trees, and people. If you see a tree with these big black ants congregating at the base, you should contact an arborist (a "tree doctor") to come have a look. Chances are good that there's a carpenter ant nest inside.

The Basics

Scientific name: Many species in the genus Camponotus

Size: Large ants, some approaching an inch in length

Identifying Features: Flat black in color, with a long oval abdomen

Feeds On: Living and dead insects and other sources of protein

Risk to People: Possible, through damage to structures and trees

Notes: Carpenter ants are one of many species with a "herding" relationship with aphids

Fire Ants

Fire Ants

Fire Ants: Genus Solenopsis

Fire ants get their name from the nature of their sting, which feels like a drop of molten lead on the skin. This is due to the mechanism of the fire ant's bite, which is more like a chemical attack. When a fire ant bites a human, it sizes a bit of skin in its sharp mandibles and cuts through the top layers. At the same time, it curls its abdomen under its body and sprays formic acid into the cut. The cut hurts, but the acid burns—this is what gives the fire ant its name; the bite literally does burn like fire. Especially bad bites develop into itchy blisters that can last for a week.

It's no wonder that the creeping invasion of fire ants into the southern United States is seen as a serious cause for alarm. A few fire ant nests in your yard can hurt your property value and hamper your enjoyment of your house and home. Fire ants are notoriously aggressive, to a degree that has to be experienced to be believed -- they will swarm up your leg, biting and burning as they go, if you stand within a few feet of their basically invisible nest. They can kill small pets, and if you're allergic, they can even kill you.

Control of fire ants has become big business as the plague spreads, And as the climate heats up, we can count on fire ants finding more and more of the United States to their liking.

The Basics

Scientific name: Several species in the large genus Solenopsis

Size: Fire ants are 3 to 5 millimeters in length

Identifying Features: These ants are small and colored red or black

Feeds On: Virtually anything living or dead that they can cut up and drag into their nest

Risk to People: Fire ants are a serious risk to people's comfort, health, and property values

Notes: Extermination may work for a fire ant infestation, depending on many factors

A fire ant close up, showing eyes, antennae, and biting mouth-parts

A fire ant close up, showing eyes, antennae, and biting mouth-parts

Fire Ant Stings Can Be a Matter of Life or Death

According to a study published in the journal PLoS One, the effects of a fire ant sting can go far beyond a simple painful moment: "Susceptible individuals who have suffered painful stings caused by red imported fire ants, Solenopsis invicta, can experience physical health effects such as fever, dizziness, generalized urticaria, or other systemic reactions such as anaphylactic shock." This severe outcome is not generally the case, but as anyone who has been stung by one of these insects knows, the bites can be extremely painful and unsettling. When fire ants bite, they generally do so in groups, and the accumulated power of the venom can sometimes cause serious health issues and even death.

This news story about the tragic outcome of a fire ant attack illustrates the threat. The man who died in this story had an allergic reaction to the bites of several fire ants, and paramedics were unable to save him. Pets, too, can fall victim to a concentrated attack by fire ants.

Fire ants live in colonies, which can contain over 200,000 ants.

Distribution of fire ants in the USA

Distribution of fire ants in the USA

My Experience With Insects

I became fascinated with insects when I was five; 50 years later, I'm still just as fascinated. I have worked in the field in various capacities for 30 years, and today I'm a dedicated citizen scientist with an ongoing project to catalog the night-flying insects of Bocas del Toro, a small island in Panama. For this project, I'm working with a permit from the Smithsonian Institution, and hundreds of my finds are in the permanent collection at the Universidad de Panama. Images and descriptions of the species I have found in the course of this project are published at

Other than my guides here on HubPages, I maintain a Facebook page, Caterpillar Identification, that has several thousand followers. On this site, I frequently identify caterpillars posted by people around the world.

Little Black Ant

Little Black Ant

Little Black Ant: Monomorium minimum

When you leave some food crumbs on the counter and come back an hour or two later and there are teeny tiny black ants swarming around it, you are witnessing the phenomenon of the little black ant. There are few insects whose common name so accurately describes the insect itself: little black ants are both little—a couple of millimeters in length, at most—and 100% black. They live in a nest of several thousand workers and one or more queens (the queens are not quite as little, measuring up to 5 mm in length).

These little insects are scavengers, feeding on everything from cake crumbs to bird droppings. Some are also predators of some kinds of moth caterpillars. As if that weren't enough, little black ants also gain nutrients by tending to aphids, which secrete a sweet liquid called "honeydew" upon which the ants feed.

The Basics

Scientific name: Monomorium minimum

Size: Tiny; about 2 millimeters in length

Identifying Features: Identified chiefly by its small size and presence in the home.

Feeds On: Literally anything

Risk to People: None, although their presence often means an unclean or unsanitary kitchen!

Notes: Almost everyone has seen these little insects on their kitchen counter or floor, but these ants get most of their nutrients from sources in the outdoors

Pavement ants, doing what they do best -- killing each other.

Pavement ants, doing what they do best -- killing each other.

Pavement Ants: Tetramorium caespitum

Pavement ants are the black ants you sometimes see swarming on the sidewalk on summer days. They are an introduced species—some say a pest, although in my experience at least they really don't do much damage—and live in nests under sidewalks throughout North America. Probably the most interesting, and most dramatic, thing about these ants is their warlike nature: "During the late spring and early summer, colonies attempt to conquer new areas and often attack nearby enemy colonies. This results in huge sidewalk battles, sometimes leaving thousands of ants dead. Because of their aggressive nature, they often invade and colonize seemingly impenetrable areas outside their native range."

Pavement ants are a harmless part of the summer fauna of virtually every town big enough to have sidewalks. If they're causing you a problem, there are plenty of natural-based ant control methods available.

The Basics

Scientific name: Tetramorium caespitum

Size: 8-10 millimeters in length

Identifying Features: Identified chiefly by its presence in large groups on summer sidewalks

Feeds On: Dead insects and other organic matter.

Risk to People: None

Notes: Almost everyone has seen these little insects on the sidewalk, sometimes in an all-out war with another colony.

Velvet Ants

Velvet Ants

Velvet Ants: Family Mutillidae

These ants are actually not ants, despite the common name—they're actually a species of wingless wasp. They get their other common name, "cow-killers" from the ferocity of their sting, which is supposed to be painful enough to kill a cow. There are many different kinds, ranging from small ant-sized species to intimidating insects over an inch in length. Some have white fur and resemble a bit of fluff from a thistle.

If you find a cow killer, take a picture, but do not try to pick it up!

The Basics

Scientific name: Family Mutillidae

Size: Most are small, but some are quite large—over an inch in length

Identifying Features: Dense "fur" or bristles; most are marked with bright red and black

Feeds On: This insect preys on spiders, caterpillars, and other insects

Risk to People: There's a chance you could get a painful sting if you mess with one

Notes: Handle these insects with care, or better, not at all.

Red Harvester Ant

Red Harvester Ant

Red Harvester Ant: Pogonomyrmex barbatus

If you live in the American Southwest, then this ant will be instantly familiar to you. Those of us in the Midwest (and beyond) never encounter them. Red harvester ants live in arid chaparral habitats, where they construct huge nests in open sandy areas. These nests are often a yard across and descend into the earth for up to ten feet, and they are home to some of the fiercest-looking ants you will find.

Red harvester ants are in the genus Pogonomyrmex. The worker ants in this genus have the most toxic venom documented in any insect, comparable to cobra venom. Of course, the amount of venom a little ant is capable of delivering is fairly small, so the sting of one ant, while definitely painful, won't seriously harm you, and there are no records of deaths from this insect.

The Basics

Scientific name: Pogonomyrmex barbatus

Size: About a half-inch in length

Identifying Features: Occurs in large nests; large, robust head; red color

Feeds On: These ants gather seeds for food

Risk to People: None

Notes: These ants are preyed upon by a species of wasp, which paralyzes the victim and uses it as a food source.

I discovered that if one looks a little closer at this beautiful world, there are always red ants underneath.

— David Lynch

Leafcutter Ants: Genus Atta and Acromyrmex

There are 47 species of leafcutter ants, all of them in the general area between South America and the American South. They have a very distinctive appearance and are generally found in parades of hundreds or thousands of individuals, marching single file and carrying overhead a sizable section of leaf. For this unique habit, they are also commonly referred to as "parasol ants." These little insects are a signature part of any Neotropical experience since it's hard to walk anywhere in a jungle without coming across them.

Cute as their behavior may seem, leafcutter ants are all business. Their social structure rivals humanity in its complex and highly diversified organization -- there are many different roles within a leafcutter colony, and differences between the groups have evolved to suit these roles to an amazing degree. For example, the soldiers who guard the column of leaf-carrying workers have huge heads and biting mouthparts, and can sting ferociously (see the above video).

Inside the nest, the ants pack the leaf fragments into a fungus-growing culture—the ants feed on this fungus, not on the leaf particles themselves. Keeping the fungus farm going requires more specialized behavior and design. This is an excellent group for advanced study by students looking for a challenging specialty.

Also worth noting is the damage that these ants can do to cultivated trees—I have witnessed the complete defoliation of a small tree in Panama in the course of one day due to an attack by Atta ants.

The Basics

Scientific name: Genus Atta and Acromyrmex

Size: Varies according to adaptations for specific roles; the largest are about a half-inch in length

Identifying Features: Generally red; many different sizes; known by their habits

Feeds On: These ants gather leaf fragments upon which they grow fungus, which is their food

Risk to People: None, although they can damage agriculture

Notes: Leafcutter ants have a social structure that rivals humans'.

The fearsome bullet ant

The fearsome bullet ant

Bullet Ant: Paraponera clavata

Bullet ants, species Paraponera clavata, are legendary for having the most painful sting in the animal kingdom—at least among insects. (for more on painful things, look into "the Schmidt Scale," and also check out the sting of the male platypus. Yes, the platypus can sting.)

As scary as this insect may seem, you really have no reason to live in fear—this ant inhabits the recesses of the Amazon rain forest, and unless that's where you live, you will likely never see one.

The Basics

Scientific name: Paraponera clavata

Size: Very large—about one inch in length

Identifying Features: Looks like a black shiny wasp with no wings (which, in some ways, is what it is)

Feeds On: Other insects

Risk to People: Potentially dangerous sting




The following sources were used for this guide:

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.


Miebakagh Fiberesima from Port Harcourt, Rivers State, NIGERIA. on May 02, 2019:

Hi, Greenmind, thanks for sharing with wonderful and colorful photos.