Allegheny Mound Ant

Formica exsectoides · Order: Hymenoptera · Family: Formicidae

Can bite. They can bite people if a mound is disturbed.

Source: Wikipedia

Allegheny Mound Ant
Photo: iNaturalist user, CC0

Allegheny mound ants have red-orange heads and thoraxes with black-brown gasters and build large solar mounds. They hunt arthropods, collect aphid honeydew, mature in 2.5 to 3 months, and have multiple queens. If a mound is disturbed they become aggressive and will bite, and their mounds can cause lesions on small trees.

Source: Wikipedia

How to recognize it

The head and thorax are red-orange while the gaster is black-brown. Members of Formica taste citrus because they produce formic acid.

Source: Wikipedia

Is it a pest in the house?

Mounds are linked to deep constriction lesions on the stems of small hardwood and conifer trees.

Source: Wikipedia

Does it bite or sting?

They will bite when their mound is disturbed.

Source: Wikipedia

Where it lives

They construct large mounds that act as solar incubators for their brood.

Source: Wikipedia

What it eats

They hunt various arthropods for protein and harvest aphid honeydew for sugars.

Source: Wikipedia

Life cycle

Development from egg to adult takes about 2.5 to 3 months. Colonies have several queens rather than a single one.

Source: Wikipedia

Where it comes from

They are native to the Atlantic region of North America. Their range extends from Nova Scotia down to Georgia.

Source: Wikipedia

Where it is found in the US

Recorded in 28 of 51 states and DC. Most records: Massachusetts, Ohio, New York, Maryland, Pennsylvania, West Virginia, Michigan, Maine.

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

Source: GBIF

Status: native in North America; native in Canada; native in United States. Source: iNaturalist

Months it is reported in the US

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Source: GBIF

More photos

Questions people ask

Do they bite?

Yes, they will bite if their mound is disturbed.

Source: Wikipedia

What do they look like?

Their head and thorax are red-orange and the gaster is black-brown.

Source: Wikipedia

What damage do they cause to trees?

Mounds can cause deep constriction lesions on the main stems of small hardwood and conifer trees.

Source: Wikipedia

Same family (Formicidae)

Sources

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

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.