Xytium

If you haven't found it yet, it's located on the northeastern side of the paint can almost directly under the "Barn Red" text

If you have a grass floor directly above the small bed, this may be what's causing the issue. After replacing the bed, I removed the floor directly above it and haven't had any issues since.

If eggs aren't spawning, the issue may be that there are too many ants somewhere outside the ant hill. I found a cluster of about 15 worker ants not far from the hill (to the northeast along one of the "paths"), and after killing them eggs began to appear. If you see a constant flow of worker ants leaving/entering the hill, eggs are most likely present. Also, if you place a lure trap surrounded by multiple spike strips (platform optional) near the hill opening, but far enough so you don't hit the spike's, you should be able to control the number of ants leaving.