The pavement ant, Tetramorium caespitum (L.), is a ground-nesting ant. The workers make nests under rocks and logs. In urban areas, they make nests under sidewalks, driveways, and slabs of homes.
The workers are about 1/8″ long. Their bodies are brown. The legs and antennae are lighter than the body. Colonies of pavement ants can have 4,000 workers and multiple queens. The queens are slightly larger than the workers, but they look similar.
In large fire ant colonies, queens can produce as many as 1,500 eggs per day. The queens of pavement ant colonies produce many fewer eggs per day. Scientists suspect that one reason pavement ant queens produce a small number of eggs may be because pavement ant colonies have fewer workers to feed and care for the immature ants as they develop. Another reason might be that since there are fewer workers in the colony, the colony needs fewer replacements for the workers that die.
Researchers have found that the number of eggs that the queen produces is related to the number of larvae that are about to change into adult ants. They have also found that there is a relation between the amount of food the queen is given and the number of eggs she produces.
During the summer, winged ants appear in the pavement ant colonies. Scientists call them alates. These are male and female ants. Their job is to fly out of their nest and mate with alates from other colonies. Because they often fly out in a sudden rush, many people call the winged ants swarmers.
After the female alates have been inseminated, they burrow into the soil to start new colonies. Scientists have found that if several inseminated females nest in the same burrow, they can start a new colony together. Research shows that their new colony has a better chance of surviving than a colony that was started by a single inseminated female alone.
As the colonies grow, they compete with neighboring pavement colonies. There are bitter struggles. Many times, the smaller colony is completely eliminated.