Ant Pile-Up (Val, Centennial, CO, U.S.A)


My buddy and I were walking back into our office today and he noticed a brown spot in the grass. Upon closer examination, we realized that it was a giant pile of ants and could not figure out what they were doing. We just wanted to know why they were all grouped up like that and what they were doing. Please let us know if you have any input - it would be greatly appreciated.

Thank you,





Hello Val,

These are the common pavement ant, variously known as Tetramorium caespitum or here at Ant Web (pending publication of research on its classification) Tetramorium species E. Originally from Europe, it is now established across the northern half or so of the US and in southern Canada, in urban areas. It has also made it to another outpost of European culture, in South America, south of Buenos Aires, Argentina! This species is famous for its pitched, but rarely lethal, territorial battles among neighboring colonies and you have found a particularly good example of this behavior.


James C. Trager of the AntAsk Team

No TrackBacks

TrackBack URL:

Leave a comment