The answer to 'what causes carpenter ant' is that carpenter ants are attracted to moist, decaying wood in and around homes. They build their nests in these areas, which can lead to structural damage if left unchecked. Carpenter ants do not actually eat the wood, but they tunnel through it to create their nests, which can weaken the wood over time.
Carpenter ants are typically found in older homes or in areas with high moisture levels, such as around leaky plumbing, poor ventilation, or in wood that has been damaged by water or other pests. They can also be attracted to food sources inside the home, such as crumbs or spills.