Alien field ant

Lasius alienus · Order: Hymenoptera · Family: Formicidae

Also called: Cornfield Ant

No source yet on danger. We have no source yet on whether it bites, stings or damages anything.
Alien field ant
Photo: unknown, CC0

Worker ants are about 2 to 4 mm long, while queens are larger at 7 to 9 mm. They are native to Europe, ranging from Spain to the Caucasus. North-American populations once called cornfield ants are now recognized as a different species, Lasius americanus.

Source: Wikipedia

Size

Workers measure roughly 2 to 4 mm, and queens are about 7 to 9 mm long.

Source: Wikipedia

Where it lives

They live throughout Europe, from Spain eastward to the Caucasus.

Source: Wikipedia

Where it comes from

Their native range is Europe, spanning Spain to the Caucasus.

Source: Wikipedia

Lookalikes

The North American “cornfield ant” is now considered a separate species, Lasius americanus.

Source: Wikipedia

Where it is found in the US

Recorded in 46 of 51 states and DC. Most records: Colorado, Illinois, Mississippi, Ohio, Tennessee, Pennsylvania, North Carolina, Virginia.

Darker = more records. Counts are museum and citizen-science records, not population size.

Source: GBIF

Months it is reported in the US

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Source: GBIF

More photos

Alien field ant photo 3
Photo: unknown, CC0

Same family (Formicidae)

Eastern Black Carpenter AntEastern Black Carpenter AntCamponotus pennsylvanicusCan damage your homeRed Imported Fire AntRed Imported Fire AntSolenopsis invictaCan stingAmerican Winter AntAmerican Winter AntPrenolepis imparisArgentine AntArgentine AntLinepithema humileNuisance, not dangerousImmigrant Pavement AntImmigrant Pavement AntTetramorium immigransCan stingOdorous House AntOdorous House AntTapinoma sessileCan damage your home

Sources

  • Wikipedia: https://en.wikipedia.org/wiki/Lasius_alienus

Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia

Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.

How this page works

This is one bug's fact sheet. The colored box at the top says whether it is dangerous. Sections below cover how to recognize it, whether it is a pest, and how to deal with it. The US map shows which states have records; tap a state to see other bugs there.

Every fact on Bug FAQ comes from a named source (university extension sites, government agencies, GBIF, iNaturalist, Wikipedia). The source is linked next to each section. If we have no source for something, we leave it out.