Bug Identifier

Ants

Carpenter Ant

Camponotus pennsylvanicus

048121620
Body length in millimeters. Shaded bar shows the typical adult range.
Scientific nameCamponotus pennsylvanicus
GroupAnts
Size6–13 mm (up to about 0.51 in)
Colors Black and Red
Legs6 legs
WingsNo (as usually seen)
Where foundIndoors, anywhere, Woods or trails, Trees or shrubs and Basement or garage
Most activeSpring and Summer
BitesYes
StingsNo
Risk levelNuisance

How to identify it

The carpenter ant is a small member of the ants group. Elbowed antennae and a pinched waist with one or two nodes. Check for these three features:

  1. Large ant with an evenly rounded, single-arch thorax
  2. One node between the thorax and abdomen
  3. Piles of coarse sawdust and insect parts near nests

About this bug

A large black ant that nests in moist or damaged wood, including window frames, decks and wall voids. It doesn't eat wood but excavates smooth galleries and pushes out sawdust-like debris.

You'll usually find carpenter ants indoors, in woods and along trails, on trees and shrubs and in basements and garages. They are most active in spring and summer.

Is it dangerous?

Carpenter ants can deliver a painful bite and weaken wood over time, but they do not carry disease.

Our rating: Nuisance, meaning it is a nuisance pest but not a health threat to most people.

When you'll see carpenter ants

Carpenter Ants are most active in spring and summer. In spring, overwintering adults become active and many species lay their first eggs. Summer heat speeds up development, so populations can grow quickly.

Typical places to check: indoors, anywhere, woods or trails, trees or shrubs and basement or garage.

About ants

The carpenter ant is one of the ants. Ants live in colonies ruled by one or more egg-laying queens. The workers you see are sterile females foraging for the rest of the colony, so killing visible ants rarely solves anything. Winged ants, called swarmers, appear when a mature colony sends out new kings and queens.

Bait works because workers carry it back and share it with the queen and larvae. Repellent sprays can scatter the colony and make the problem harder to fix.

What to do about it

  1. Follow trails at night to find the main nest and satellite colonies
  2. Fix leaks and replace water-damaged wood
  3. Use a slow-acting bait or call a professional for nests inside walls

Read the full guide: how to get rid of carpenter ants.

Bugs that look similar

Eastern Subterranean TermiteReticulitermes flavipes3–10 mmNuisance

Group: Carpenter Ant belongs to ants, while eastern subterranean termite belongs to termites. Elbowed antennae and a pinched waist with one or two nodes.

Pavement AntTetramorium immigrans2.5–4 mmNuisance

Size: Carpenter Ants are larger, reaching 13 mm, while pavement ants top out around 4 mm.

Frequently asked questions

What does a carpenter ant look like?

Large ant with an evenly rounded, single-arch thorax. Adults measure 6–13 mm (up to about 0.51 in).

Does the carpenter ant bite or sting?

It can bite. It does not sting. Carpenter ants can deliver a painful bite and weaken wood over time, but they do not carry disease.

Where do carpenter ants live?

Carpenter Ants live indoors, in woods and along trails, on trees and shrubs and in basements and garages.

When are carpenter ants most active?

Mostly in spring and summer.