Argentine Ants

The Argentine ant (Linepithema humile, formerly Iridomyrmex humilis) is a tiny dark ant native to northern Argentina, Uruguay, Paraguay, and southern Brazil. The species has been inadvertently introduced by humans to many other areas of the world, such as South Africa, New Zealand, Japan, Easter Island, Australia, Hawaii, Europe, and the United States.

The worker ants are only about 3 mm (1/8th inch) long and can easily squeeze through cracks and holes no more than 1 mm (0.040 inch) in size. Queens are two to four times the length of workers. These tiny ants will set up quarters in the ground, in cracks in concrete walls, in spaces between boards and timbers, even among belongings in human dwellings.

German entomologist Dr. Gustav L. Mayr identified the first specimens of Hypoclinea humilis in the vicinity of Buenos Aires, Argentina in 1866. This species was shortly transferred to the genus Iridomyrmex, and finally to Linepithema in the early 1990s.

Source: http://antfarmz.net