Keep and eye out around your home for little piles of what looks like sawdust. It can be easy to overlook or ignore, but those little piles of sawdust are an indication that you have a carpenter ant problem.
Carpenter ants burrow and tunnel into wood to make their homes (no they do not eat wood like termites). They will do this anywhere...posts, decks, furniture...inside or outside your home.
To deal with them you first want to eliminate what they are after which is food and water. Just like any other ant or pest, things like water leaks, trash, dirty dishes, open dog food containers, unsealed cookies etc. etc. etc. are all open invitations for carpenter ants. Give them food and water, and they will use the wood in YOUR home to make THEIR home.
After "tidying up", a pest control application is the next step. Regular exterior pest control applications will keep them out of your home for the most part. But its still a good idea to treat them as needed while doing regular inspections both inside and outside of your home.