Destructive trailing ant

The worker is variable in size, from 1.8 to 3.5 millimeters (0.07 to 0.14 inches) in length, and color, from light yellow to darker brownish yellow, but usually with a "chocolate" abdomen. It has a square head and 12-segmented antennae with club-like tips. Each mandible has three large teeth and a much smaller fourth tooth. The body is mostly smooth and shiny with erect setae. The queen ant is between 3 and 4 millimeters (0.12 and 0.16 inches) long and tawny in color with a brown abdomen. The head is more rectangular. The setae on the front part of the body are more curved and those on the abdomen are more flat than erect. This species is similar to Trichomyrmex robustior and Trichomyrmex mayri, which are darker in color, and M. latinode, which has five teeth per mandible instead of four.

This is a "tramp ant", an invasive ant species that easily becomes established and dominant in new habitat due to traits such as aggression toward other ant species, little aggression toward members of its own species, efficient recruitment, and large colony size. As a tramp ant, it has spread throughout the world via human transport systems, particularly shipping. It is introduced with freight in a variety of transport modes. Today it can be found in tropical regions worldwide, and it can live in urban environments in temperate climates. It is present in or has been reported from many countries and islands in Asia, Africa, Australasia and other Pacific Islands, the West Indies, North, Central, and South America, and Europe. It is most widely distributed in the Old World, and it is very common in the Pacific Islands. Its native range is unknown. It has been hypothesized that it originated in India and perhaps other Asian countries, or Africa. Considering its close resemblance to African Monomorium species and its apparently continuous distribution from North Africa to Southeast Asia, its native range may include southern Asia and the Middle East, and it may have originated in North Africa.