Black Carpenter Ant

Camponotus pennsylvanicus

Edward H. Holsten

Carpenter Ants are one of our most common ants. They are found in dead wood, such as trees, fallen logs, stumps, or even in houses.

Carpenter Ants are mostly black, usually ranging from 1/4 inch to 1/2 inch. They sometimes have a brown thorax (middle section). If you look carefully, you can see yellowish hairs on the abdomen (back section).

The queen ant is larger, up to 3/4 inch. "Swarmers," winged male and female ants who are born in the Spring in order to mate are also about 3/4 inch.

Jim Kalisch

Carpenter Ants live in colonies. When the swarmers leave a colony in the Spring, males and females will mate. The males will then die and the females will lose their wings.

Each wingless female will try to become queen of a new colony. She will first seek out a good site, usually moist dead wood which has been weakened by fungus.

Once she has found a good site, she will lay up to 20 eggs.

Carpenter Ants go through several stages. They will develop as eggs for about three weeks. Then they will spend approximately another three weeks as larvae. Carpenter Ant larvae are small, white, and legless, resembling maggots (fly larvae). They will spend a final three weeks as pupae. This is the resting stage where they will form a small tan capsule, before emerging as adult ants.

The ants which come out of the pupae will be female worker ants. They are sterile (unable to breed). These workers will eat fluid given to them from the queen. When they are strong enough, they will begin gathering food and enlarging the nest. The queen will also lay more eggs, and the workers will care for them. The queen's only job now is to lay eggs.

All of the new eggs will become female workers. In a few years, there will be thousands of ants in the colony. Two "levels" of workers will form: major workers and minor workers. Major workers will guard the nest, battle intruders, explore, and find food. Minor workers will expand the nest, and care for the young.

When a worker finds food, she will leave a scent trail on her way back to the colony. When she arrives, she will wiggle her abodomen to let other workers know she found food. They will then go out and follow her trail to the food source.

Workers in the nest will regurgitate (throw up) food for the queen and the larvae.

After a few years, when the colony has become successfull, the nest has been expanded, and thousands of ants are present, the queen will produce eggs which will become swarmers. These males and females will mate and continue the cycle.

Carpenter Ants eat mostly honeydew. Honeydew is a secretion from insects called aphids. Another group of insects which make honeydew used by ants are scale insects. Besides honeydew, Carpenter Ants will eat nectar from flowers, fruit juice, other insects, and even dead Carpenter Ants from their own colony. These ants look for food mostly at night, but they rarely travel more than 100 yards away from the nest.

Only one queen will be in a single colony. She will lay thousands of eggs in her lifetime, including swarmers, some of which will become queens in new colonies.

Carpenter Ants do not eat wood, they only dig out galleries (rooms and hallways) in it. Special chambers are used to store eggs, larvae, and pupae as they grow.

Carpenter Ants are an important food source for woodpeckers and other animals. Pileated Woodpeckers are known for rooting out and swallowing entire colonies.

Additional Media

Carpenter Ant Feeding #1
Virginia Tech Entomology Department
Carpenter Ant Feeding #2
Virginia Tech Entomology Department
Carpenter Ant Feeding #3
Virginia Tech Entomology Department
Carpenter Ant Feeding #4
Virginia Tech Entomology Department
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Relationships in Nature:


Giant Willow Aphid

Pileated Woodpecker

Black Willow

Giant Willow Aphid Mu


Downy Woodpecker

Black Oak

Bracken Fern Mu

Bull Thistle

Rabid Wolf Spider

Virginia Pine

Blue Jay

Common Milkweed

Red-backed Salamander

Yellow Poplar

Soil Mite C

Bracken Fern

American Toad

Eastern White Pine

Oystershell Scale Mu

Field Cricket

Wood Frog

American Sycamore

Black Carpenter Ant

Wild Turkey

Poison Ivy

Highbush Blueberry

Big Brown Bat

Virginia Creeper

Queen Anne's Lace

Yellow Perch

Bracken Fern

Black Cherry

Garden Centipede

Cinnamon Fern

Oystershell Scale


Japanese Honeysuckle

Painted Lady

Creek Chub

Black-eyed Susan

Fiery Searcher

Ruby-throated Hummingbird

Bird-foot Violet

Green Stinkbug

Northern Ringneck Snake

Wild Strawberry

Snow Flea

Spring Peeper

British Soldiers

Eastern Subterranean Termite

Striped Skunk

Differential Grasshopper

Black and Yellow Argiope

Black-eyed Susan

Carolina Chickadee

Soil Mite

Eastern Mole


Six-spotted Tiger Beetle

Relationship to Humans:

Carpenter Ants are helpful to people because they help break down dead wood, such as old trees, stumps, and logs. They can also be a pest when they enter homes or start colonies in man-made wooden objects, such as walls or poles. Usually this wood is already damaged, but the ants can make it worse.


Camponotus pennsylvanicus


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