Carpenter ants excavate wood and form smooth tunnels inside. They tunnel through and chew to create nests without eating the wood. These pests are black and form large colonies that can contain up to 50,000 individuals.
Since they do the majority of the damage internally in a home, the only external sign of their presence is the appearance of small openings on the surface of wood, and sawdust like shavings. They prefer to tunnel in wood softened by fungus and are typically affected by moisture problems.
To prevent an infestation, eliminate sources of moisture or standing water. Keep outside plants cut back from your house and make sure there are no cracks or openings around the bottom of doors or around windows.