# Pharaoh ant

*Monomorium pharaonis*

**Identification confidence:** Needs an expert — Pharaoh ants are easily confused with other tiny yellowish ants, and the distinction matters a great deal in hospitals and multi-unit housing. Have a specimen identified rather than guessing — your county extension office will often do it at no cost.


## How to recognise it

- Very small at under 2 mm and pale yellow to light golden brown, often with a darker abdomen tip, appearing almost translucent against a white surface.
- Two nodes on the waist and three-segmented antennal club, which requires magnification to see.
- Workers are uniform in size and move in slow, steady trails, frequently along plumbing and electrical runs.

## What it leaves behind

- Persistent indoor trails in heated buildings year-round, including in winter.
- Activity concentrated around water sources, bathrooms, and kitchens in apartment buildings and institutions.

## Why an infestation persists

This species is the reason identification matters in multi-unit housing. Colonies have many queens, nest deep in wall voids and equipment, and respond to disturbance by budding into multiple new colonies — so an untargeted spray application reliably makes a pharaoh ant problem larger and spreads it to neighbouring units. Coordinated building-wide management is the only approach that works.


## Where it occurs

Throughout the United States as an indoor pest; cannot survive outdoors in most of the country and is essentially always a building-associated population.

## What prevents it

- Report activity to building management early, because a single-unit response cannot resolve a building-wide population.
- Keep food sealed and surfaces dry; deny the moisture these colonies depend on.
- Do not apply repellent products, which cause colonies to bud and spread.

## Commonly confused with

- **Little black ant** (*Monomorium minimum*) — Extremely small at 1.5 to 2 mm, noticeably smaller than pavement or odorous house ants seen alongside them.
- **Thief ant** (*Solenopsis molesta*) — Among the smallest household ants at under 2 mm, pale yellow to light brown.

**Verdict:** professional-recommended. Budding behaviour means uncoordinated treatment makes it worse, and in multi-unit buildings the population usually spans units. This needs a building-wide plan, not a unit-by-unit reaction.


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