Is it a carpenter ant?
The carpenter ant is a large black or reddish-black ant commonly found nesting in moist or decaying wood in and around residential structures.
whichbug identifies insects from what you can see. It does not identify bites and has no health information.
What to look for
| Size | 6-13 mm |
|---|---|
| Colour | Black, dark brown, or reddish-brown, often with a uniform dark appearance |
| Shape | Elongated body with a single node between the thorax and abdomen and a smooth, rounded thorax profile |
| Wings | Present in reproductive castes; four wings with the front pair larger than the hind pair |
| Antennae | Elbowed with 12 segments |
| Movement | Fast and agile runners that navigate wood surfaces and walls |
Where you'll find them
Wall voidsAttic spacesWindow and door framesBasement crawl spacesOutdoor decaying stumpsstructural pest
These ants excavate wood to create nesting galleries, which can compromise the structural integrity of timber over time.
Season: Spring through late summer
Signs it's around
- Sawdust-like frass (wood shavings) pushed out of small exit holes
- Smooth, clean galleries inside wood that resemble sandpapered surfaces
- Presence of winged reproductive ants swarming indoors
- Rustling sounds within walls at night
Not sure? The lookalikes
| vs termite | Carpenter ants have elbowed antennae and a pinched waist, whereas termites have straight antennae and a thick, uniform waist. |
| vs black garden ant | Carpenter ants are significantly larger and have a single-segmented node at the waist, while black garden ants have a two-segmented node. |
| vs field ant | Carpenter ants have a smooth, rounded thorax in profile, whereas field ants have a thorax with distinct bumps or a serrated appearance. |