A mode of life in which one species spends all or part of its existence in close contact with, and at the expense of, another species is rather common among ants. Sudd (1%7) stated that about one sixth of all known European species are parasitic to some extent. At the Edwin S. George Reserve in Livingston County, Michigan, 28.7% (25 of the 87 species) fall into the category of forms considered to be in some way parasitic on other ants.
"Social Parasitism Among Ants at the E.S. George Reserve in Southern Michigan,"
The Great Lakes Entomologist: Vol. 12
, Article 7.
Available at: http://scholar.valpo.edu/tgle/vol12/iss2/7