All species of carpenter ants mainly attack wood that is or has been wet and damaged by mold. Even though these black carpenter ants first invade wet, decayed wood, they may soon begin building paths through dry, undamaged wood. They usually come into buildings through cracks around doors, windows, or through holes for wires. They will also crawl along overhead wires, shrubs, or tree limbs that touch the building far above the ground.
Carpenter ants build their nests outdoors in various wood sources, including tree stumps, firewood or landscaping. They need a constant water source to survive. Carpenter ants will enter the house through wet, damaged wood.