The largest recorded colony of ants in the world stretches 6,000 km (3,700 miles) from northern Italy, through the south of France to the Atlantic coast of Spain, and is made up of a species of Argentine ant (Linepithema humile) introduced into Europe approximately 80 years ago. 

The ants have shown the ability to recognise each other even though they may come from opposite ends of the colony. The discovery of  the ‘supercolony’ is the result of research carried out by Swiss, French and Danish scientists whose findings were published in The Proceedings of the National Academy of Sciences.

The workers are 2–3 mm in length.