# Pavement ant

*Tetramorium immigrans*

**Identification confidence:** Identifiable with care — The paired thoracic spines and head grooves are visible with a hand lens and are decisive.

## How to recognise it

- The head and thorax carry fine parallel grooves running front to back, visible under a hand lens as a striped or engraved texture.
- There are two small spines projecting backward from the rear of the thorax, and two nodes on the waist rather than one.
- Colour is dark brown to black with paler, often yellowish legs and antennae.
- Workers are uniform in size at roughly 3 mm.

## What it leaves behind

- Small mounds of excavated soil pushed up through cracks in driveways, patios, and sidewalk joints.
- Large numbers of workers on paving in spring, sometimes in mass confrontations between neighbouring colonies.

## Why an infestation persists

Nests are outdoors under slabs, stones, and paving, and workers enter buildings to forage rather than to nest. Indoor activity is usually a foraging trail from an outdoor colony, so the entry point matters more than anything found indoors.


## Where it occurs

Common across the eastern and midwestern United States and increasingly reported in the West; strongly associated with paved and disturbed urban ground.

## What prevents it

- Seal the expansion joints and foundation cracks the trails emerge from.
- Keep food debris off patios and around outdoor bins.
- Reduce moisture along the slab edge where colonies concentrate.

## Commonly confused with

- **Odorous house ant** (*Tapinoma sessile*) — Crushed workers give off a distinct sweet, musty smell often described as rotten coconut or blue cheese. This is the definitive field test and no other common household ant does it.
- **Little black ant** (*Monomorium minimum*) — Extremely small at 1.5 to 2 mm, noticeably smaller than pavement or odorous house ants seen alongside them.
- **Red imported fire ant** (*Solenopsis invicta*) — Reddish-brown head and thorax with a darker abdomen, and workers of clearly varying sizes within one colony.

**Verdict:** prevention-first. Pavement ants nest outdoors and forage in; sealing the entry route and removing the attractant resolves most indoor complaints.

Source: https://againstpest.shop/identify/ants/pavement-ant/