This number doesn't surprise me. I live within the Arctic circle and there are a lot of wood ants [0] in my area. Among the various reasons wood ants are fascinating (aphid farming, formic acid spitting/squirting) is that they live in very large mounds that can reach several feet high.<p>Each of these mounds are estimated to have a population ranging from 100,000 to over one million and there can be dozens of them within a 100m × 100m square. I imagine it similar to the state of New York full of NYCs, just a few miles between each. A Finnish study found that these mounds can be connected into super-colonies which span kilometers. [1]<p>I have also lived in California and have experienced red ants beginning to stake out territory near or in my home. Remember that they are not there just <i>because</i> of the food sources, but <i>in spite</i> of us making the terrain otherwise utterly inhospitable to them with pavement, insecticide, diatomaceous earth, and all of that. And still they can be incredibly difficult to get rid of.<p>The way they operate as a colony makes them very interesting. I can see why so many people have caught the ant-fascination bug.<p>[0] <a href="https://en.wikipedia.org/wiki/Formica" rel="nofollow">https://en.wikipedia.org/wiki/Formica</a><p>[1] <a href="https://pubmed.ncbi.nlm.nih.gov/27859791/" rel="nofollow">https://pubmed.ncbi.nlm.nih.gov/27859791/</a>