carpenter ants

You have a water leakage problem. As others have said, the thrive on damp wood and tunnel. We had a house once and I could hear them 10 feet away from a window. When I looked I saw their legs coming up through a crack in the sill. Water had leaked in when the window was left open during heavy rain. We called an exterminator. You need to find the leak, besides eradicating them.
There is a Florida Carpenter ant as well.
http://entnemdept.ufl.edu/creatures/urban/ants/fl_carpenter_ants.htm