Bug FAQMonomorium ergatogyna
Monomorium ergatogyna · Order: Hymenoptera · Family: Formicidae
Monomorium ergatogyna is a shiny black ant with only one worker caste, making it monomorphic. It is native to California, Nevada, and Utah, typically found in cities, along the coast, and on nearby islands. Queens can live up to two years in captivity, the longest among related species.
Source: Wikipedia
How to recognize it
The ant is shiny black and has only a single worker caste, so all workers look the same.
Source: Wikipedia
Where it lives
It is usually found in cities or along the coast, and on islands near the coast in California.
Source: Wikipedia
Life cycle
Queens can live up to two years when kept in captivity, longer than most Monomorium species.
Source: Wikipedia
Where it comes from
It is native to California, Nevada, and Utah.
Source: Wikipedia
Lookalikes
It is often confused with Monomorium carbonarium because they look similar.
Source: Wikipedia
Where it is found in the US
Recorded in 7 of 51 states and DC. Most records: California, Utah, Arizona, Nevada, Texas, New Mexico, Idaho.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
How can I tell Monomorium ergatogyna apart from similar ants?
It is a shiny black ant with a single worker caste, while the look-alike Monomorium carbonarium looks similar but is a different species.
Source: Wikipedia
What is causing this ant to disappear from its area?
Argentine ants (Linepithema humile) are actively displacing it from its native range.
Source: Wikipedia
Same family (Formicidae)
Eastern Black Carpenter AntCamponotus pennsylvanicusCan damage your home
Red Imported Fire AntSolenopsis invictaCan sting
American Winter AntPrenolepis imparis
Argentine AntLinepithema humileNuisance, not dangerous
Immigrant Pavement AntTetramorium immigransCan sting
Odorous House AntTapinoma sessileCan damage your homeSources
- Wikipedia: https://en.wikipedia.org/wiki/Monomorium_ergatogyna
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-24.