Linepithema humile (Mayr, 1868)

Description and notes

Linepithema humile (formerly Iridomyrmex humilis) better known as The Argentine Ant originates from South America. It has been spread by humans to many parts of the world and has become established in areas that have a warm climate. It has only rarely been found in Britain and then usually in hothouses or buildings. It is an invasive species which forms large or very large colonies of cooperating, interconnected nests with many queens.


LINEPITHEMA humile distribution map

Very localised usually in hot-houses or other heated buildings. A large colony, living at least partly outdoors, is known from Fulham in West London.

A world-wide tramp species found in most places with a warm climate. Such as southern Europe.

Status (in Britain only)

A non-native invasive species


They are somewhat smaller, paler and more slender than the very common black ant Lasius niger. The posterior of the gaster has a sideways slit and not an acidipore. The single petiole is large.

Foraging behaviour

Aggressive ants. They will attack and kill other ants species and other invertebrates.


Omniverous. Invertabrates, honeydew from aphids, anything they can scavenge.

Reproductive behaviour

Females mate in the nest and start laying eggs very soon afterwards.

Author of profile

M G Fox

Year profile last updated