Carpenter ants are sizable insects known for creating nests by hollowing out wood, which can compromise structural integrity. They prefer moist or decaying wood and are often found in areas like attics, basements, and wall voids. Signs of infestation include the presence of large black ants, especially at night, and small piles of wood shavings (frass). Unlike termites, they do not consume wood but remove it to expand their nests.