Piles of black ants are often seen on sidewalks and driveways. These ant piles may be very large and can be composed of thousands of ants. These ants are pavement ants. Pavement ants congregate in piles for two main reasons. The first reason is because neighboring colonies of pavement ants go to war with one another. At first glance, this appears as a pile of black ants that are simply crawling over each other. But a closer look reveals that the ants are engaged in battle. The second cause of ant piles is that they have found a food source. The worker ants swarm onto the food, and then carry it back to their colony. Pavement ants are known to nest in cracks along sidewalks, beneath cement slabs, and along the edges of driveways. Tiny mounds of dirt are sometimes present above the entrance to the colony. These mounds are made from the excavated dirt produced during tunneling. They are most easily seen between cement slabs of a sidewalk.
What are the implications of an ant pile? These piles show that ant colonies are established in the area. Pavement ants don’t typically inhabit homes. If these ants are spotted inside a home, it is usually because they have found a food source and are carrying it back to the outside colony. Pavement ants do not damage the structure of a home, but their presence can be a nuisance.
Ant bait is an effective method of control for an ant pile made by pavement ants. Slow acting bait allows workers to carry the poison back to the rest of the colony. Pavement ants can enter a home through cracks in the cement foundation. Locate these cracks by following the trails of ants. Once the entry crack has been located, caulk it closed. Insecticide is also effective, but be sure to follow the label in order to avoid harming children and pets.