This I'm certain is a Formica worker. I was hoping to narrow it down to at least a few possible species groups. I realize this might not be possible.
1. She was on a myrmecophilious plant in a local nature park.
2. Found 21 June, 2019
3. In a prairie type setting, somewhat dense foiliage nearby. No trees in the immediate area.
4. 6mm
5. Solid black
6. Abdomen somewhat pilose