Pavement Ant

Tetramorium immigrans, commonly known as the pavement ant, is a small, dark brown ant measuring approximately 2.5–4.0 mm in length. A key identifying feature includes distinct parallel grooves or striae on the head and thorax, visible under magnification, and a 12-segmented antenna ending in a 3-segmented club. Colonies are typically monogynous, with a single queen, though polygnous populations with multiple queens have been observed, ranging in size from 3,000 to 10,000 workers or more. Queens can live for several years, with worker lifespan generally 1-3 years; complete metamorphosis includes egg, larval, pupal, and adult stages, with eggs hatching in 2-3 weeks and pupal development taking 2-3 weeks, optimal development occurring between 24-30 degrees Celsius and moderate humidity. Reproductive swarms of winged alates occur from late spring to mid-summer, dispersing to establish new colonies.

Pavement ants exhibit primarily nocturnal foraging behavior, though activity is also observed during daylight hours, especially in cooler conditions or shaded areas. They are highly social, communicating through chemical pheromone trails laid by successful foragers to guide nestmates to food sources. While generally not aggressive towards humans, they will readily bite and sting when their nest is disturbed, though their sting is typically mild and non-venomous. Their omnivorous diet includes a wide range of proteins, carbohydrates, and fats, demonstrating adaptability in food acquisition. Within a colony, workers are responsible for foraging, nest maintenance, and brood care, exhibiting a division of labor crucial for colony survival and growth.