The pavement ant, Tetramorium caespitum, is a common household pest. Its name comes from the fact that colonies usually make their homes in pavement. It is distinguished by one pair of spines on the back, two nodes on the petiole, and grooves on the head and thorax. The species is native to Europe, but was introduced to North America in the 18th century.
During early spring, colonies attempt to conquer new areas and often attack nearby enemy colonies. These result in huge sidewalk battles, sometimes leaving thousands of ants dead. Because of their aggressive nature, they often invade and colonize seemingly impenetrable areas. In summer time the ants dig out the sand in between the pavements to vent the nests.
The pavement ant is dark brown to blackish, and 2.5–4 mm long. Like other ants there are the workers, alates, and a queen. Alates, or new queen ants and drones, have wings, and are twice as large as the workers.
The drone’s only job is to mate with the queen, and reproduction is at its highest in spring and summer. Tetramorium, like many other ants have nuptial flights where drones fly high up in the air and mate with new queens. The queen finds a suitable nesting location and digs a founding chamber. As the eggs hatch and the ants develop they will spend that time, about two to three months, tending to the queen of their colony. They will continue helping in the colony until they are a month old. Older workers hunt and defend the colony. They will eat almost anything, including insects, seeds, honeydew, honey, bread, meats, nuts, ice cream and cheese.