A good natural way I found of getting rid of carpenter ants or any ants in my home for that matter is to take some bakers yeast and put it where the carpenter ants or other ants are crawling around.
The ants will then eat the bakers yeast and it will swell their insides out and then it will kill the ants.
You could also put out some roach motels or other sticky pads where the ants will crawl into or on the glue pads get stuck and not be able to get off.