Allegheny Mound Ant

Formica Excetoides

Allegehny Mound Ant (Formica exsectoides)
  • Ryan Hodnett, CC BY-SA 4.0, via Wikimedia Commons
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    • Color: Reddish with black abdomen
    • Worker size: 4.5-7 millimetres
    • Colony size: 250,000
    • Queen: 3/8-1/2 inches, parasitic, polygynous

    Introduction

    Allegheny Mound ants, as their name suggests, build towering mounds! They have reddish thoraxes and heads, with a black abdomen. They are 4.5-7 mm long. Their queens range from 3/8-1/2 inches long.

    Unique Traits

    Mountainous Castles

    These ants build huge mounds that can be up to 3 feet tall (0.9 metres) and 8 feet across. Now that’s HUGE! You could tell roughly how mature the colonies are by looking at how big their mounds are. More ants equal bigger mounds. These mounds help ants get the right temperature and humidity at the right time. Mounds also have a sort of “thatched roof”. These roofs are 2-3 inches thick and are made with finely chopped twigs, which resist harsh weather like rain. Allegheny Mound ants make their nests with the soil dug from their nests, and other dead biomatter such as dead leaves and twigs.

    Invasion!

    These ants have an interesting way of reproduction. Their queens infiltrate another colony like Formica subsericea. The F. exsectoides queen will endeavour to kill the other queen, or be killed. If they succeed in killing the F. subsericea queen, then the Allegheny Mound ant queen will lay eggs, and the workers of the already established F. subsericea are forced to care for them. Finally, the F. subsericea workers die off, leaving only the Allegheny Mound ant workers that they cared for.

    Defences

    Allegheny Mound ants, like a lot of other ant species, use formic acid to defend themselves. They bite on their victim and squeeze the formic acid into the wound they caused. These ants will also bite any intruder who disturbs their nest.

    Habitat & Diet

    These ants build their mounds in areas not frequently mowed, and could be a problem in some tree farms. This is because they kill the vegetation around them by injecting it with acid. This may help them expand their colonies. They are native to North America and seem to enjoy living in Jack Pine tree forests (Pinus banksiana) in the Great Lakes region. These ants are also very picky about where they nest. They usually like to nest in sunlit areas, not with any shade. These ants mainly eat sugary foods (like honeydew) and harvest them from insects on plants.

    Sources:

    Written by: Eric Qian