The answer to 'why is my carpenter ant nests' is that carpenter ants build nests inside wood structures to create a home and raise their young. Carpenter ants do not actually eat the wood, but instead tunnel through it to create their nests. Common signs of a carpenter ant infestation include seeing the ants themselves, piles of wood shavings, and damaged wood structures.
To solve a carpenter ant problem, it's important to locate and eliminate the main nest. This may involve treating the nest with insecticide or physically removing the infested wood. For DIY treatment, baits and sprays can be effective, but for large or hard-to-reach nests, it's best to call a professional pest control technician who can properly identify the issue and apply the right treatment.