The Field Museum ant collection is worldwide in scope and includes the important Robert E. Gregg Collection among others. Although the majority of the Gregg collections are from the USA, it also includes important collections from around the world. There are also extensive wet (70% alcohol preserved) worldwide collections due to the efforts of previous collectors including H.S. Dybas and S.B. and J. Peck (many of these bulk arthropod samples have not yet been sorted for any taxonomic groups). Specimens from each species stored in the wet collection are being mounted and added to the pinned collection. The thousands of pinned ants are currently being inventoried, databased and given unique identifiers. As the pinned material is databased, it is being made available on our online EMu collection database.
The Field Museum ant collections are in four (broad) categories with only the pinned material fully databased: 1) Pinned, fully databased material; 2) Robert Gregg wet collections (70% ethanol), which are identified to genus and in most cases to species, although they often follow old nomenclature and taxonomy - we are working on slowly databasing the entire very large collection; 3) wet collections (70% ethanol) usually not collected by Robert Gregg and often not sorted past Formicidae or sometimes genus; and 4) completely unsorted "bulk" samples (again in 70% ethanol) which are the mixed arthropods from passive collecting methods from around the world which you can search by location or collection method: http://fieldmuseum.org/explore/our-collections/bulk-sample-collection
To search for all ants at the search link, enter Formicidae in the Family field: http://emuweb.fieldmuseum.org/arthropod/arthropod.php