Odorous house ant vs Ghost ant
These two are easy to mix up. Here's how to tell an odorous house ant from a ghost ant, and whether either one bites or stings.
Odorous house ant
Tapinoma sessile
Ghost ant
Tapinoma melanocephalum
≠The key differences
Odorous house ants are more uniformly brown and emit a strong coconut-like odor when crushed; ghost ants have a clear two-tone appearance and are smaller.
⚖︎Side by side
| Odorous house ant | Ghost ant | |
|---|---|---|
| To humans | Non-toxic | Non-toxic |
| Size | Workers 2.4-3.3 mm long; queens larger (about 4-5 mm) | Workers 1.3-1.5 mm long |
| Colours | Light brown, Dark brown, Black | Black (head and gaster), Dark brown, Pale yellow (thorax, legs, antennae) |
| Family | Formicidae | Formicidae |
| Habitat | Urban and suburban areas, inside buildings (kitchens, wall voids), under stones, wood, mulch and in soil; tolerant of varied habitats | Warm, humid, protected microhabitats: inside buildings (wall voids, kitchens), potted plants, greenhouses, under bark and leaf litter in warm climates. |
| Range | Native to North America and widespread across the United States and southern Canada; found in diverse habitats from forests to cities | Tropical and subtropical worldwide; now cosmopolitan in greenhouses and human structures across all continents except the coldest regions. |
| Active | Active year-round in heated buildings; outdoors mostly spring to fall and during warm parts of the day | Active year-round in warm indoors or tropical climates; outdoors in warmer months in subtropical/temperate areas; mainly diurnal but can forage at any time. |
| Pest? | Yes | Yes |
🔍How to spot an odorous house ant
- Very small workers (2.4-3.3 mm) with a smooth profile because the petiole is hidden by the gaster
- Colour variable from light brown to dark brown or black
- When crushed, workers give off a distinctive odour often described as rotten coconut, pine, or moldy cheese
- Do not have a distinct antenna club and have 12-segmented antennae
🔍How to spot a ghost ant
- Very small workers (about 1.3-1.5 mm) — much smaller than many common house ants.
- Dark head and gaster contrasted with a pale, almost translucent thorax, legs and antennae.
- Glossy body and smooth appearance; no visible sting or two-segmented petiole from above.
- Sweet-foraging trails in kitchens and near sinks; nests often hidden in potted plants or wall voids.
?Frequently asked questions
What is the difference between an odorous house ant and a ghost ant?
Odorous house ants are more uniformly brown and emit a strong coconut-like odor when crushed; ghost ants have a clear two-tone appearance and are smaller.
Is an odorous house ant or a ghost ant more dangerous?
Odorous house ant: Non-toxic. Ghost ant: Non-toxic. Odorous house ants do not have a sting. Ghost ants do not sting and rarely bite; they are primarily a nuisance.
Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.