oh yeah, I found it. I'm 90% sure. It was wonderfully hot this weekend, and my family was hanging out on the patio. My husband commented that the patio had a lot of carpenter ants. I began searching in the yard and found a HUGE carpenter ant nest about 15 feet from our home. We have a concrete walkway that has decorative cedar strips between the concrete slabs. This huge ant hill probably started on one of those strips. But now, it likely goes underneath the concrete, and runs along the edge of the walkway. I'd estimate that the exposed portion is over 6 feet long!
How to kill the colony? I'm concerned that much of it is protected by the concrete slabs. Bait? Please recommend specific products, if possible.