Carpenter ants like a warm moist area to nest. Could be an area that is collecting moisture or it's a great place for them to nest, being close to a food supply. They will eat most everything we eat, but some are more "grease "eaters and some are "sweet" eaters. , they normally come out at dark and will trail so with your flashlite you can watch where they are going in and out. Next if you find the nest you can spray with any of the can sprays you have (ant,roach etc). If this doesn't work then you must bait them. For the sweet eaters you can put out some Terro ant bait( walgreens,ace hardware. Box depot stores). And or boric acid powder. Mix the boric acid about 20 percent with peanut butter 80 percent. Can place on small pieces of cardboard. The baits should be very small like size of a dime, then place several around their trailing area. When baiting suspend Spraying. The Terro the same way small amounts but several locations. Give them plenty then they will not go for your food. Hope this helps out.
Jerry. Vietnam vet.