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 spine 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,.. more