Several biological factors ensure the success of this species as a notorious pest. These include: multi-queened (polygynous) colonies – hence a high fecundity; large numbers of offspring and rapid recruitment lead to dominance over larger ants at food sources; an ability to exploit a diversity of habitats and food sources; a propensity for forming supercolonies through successful mixing of individuals from separate nests that are linked by foraging trails.
Argentine ant workers are only 2–3 mm long and are a uniform honey-brown colour. Foraging ants move steadily in defined continuous trails that can often be seen going up trees or shrubs, especially if these are flowering. The ants can't sting but some people react to their bite.