Carpenter Ants are typically more visible at night because they are nocturnal.

To prevent Carpenter Ant problems:
(1) Eliminate high moisture conditions that are attractive to them.
(2) Replace any moisture-damaged wood.
(3) Be careful that wood or lumber that is stored in a garage or near the house is kept dry and, if possible, elevated to allow air circulation.
(4) Store firewood as far away from buildings as possible.
(5) Remove tree and shrub stumps and roots.
(6) Trim branches that overhang the home, buildings or electrical wiring to avoid giving carpenter ants easy access.
(7) When possible, remove wood that contains carpenter ant nests, and destroy the colony by having a professional treatment done.