Formicine-ant
Guides
Brachymyrmex patagonicus
Dark Rover Ant, Black Rover Ant
Brachymyrmex patagonicus is a small invasive ant native to South America that has established populations across the southern United States, Europe, Asia, and the Caribbean. Workers are diminutive (1.0–2.0 mm), brown to black, with nine-segmented antennae and relatively large eyes compared to congeners. The species exhibits an unusual multicolonial social structure for an invasive ant, with most colonies consisting of a single nest headed by one queen, maintaining aggression toward non-nestmates rather than forming supercolonies. It is a significant nuisance pest of buildings but does not bite, sting, or vector disease.
Lasius emarginatus
ManhattAnt, Central European Bicolored Ant
Lasius emarginatus is a small formicine ant native to western Eurasia that has become a notable invasive species in North America. First discovered in New York City in 2011, it earned the nickname "ManhattAnt" and has since become one of the most common ants in the city, spreading at approximately 2 km per year into New Jersey and Long Island. Workers are distinguished by their reddish-brown thorax contrasting with darker brown head and abdomen. The species is increasingly reported as an indoor pest and forms mutualisms with honeydew-producing insects on street trees. Unlike many invasive ants, it does not display supercolonial behavior.