I'm not sure if the identification is correct. The small ant appeared to have similar markings and colouration to a Kilian's ant. I think this is a Queen as there are the partially removed wings visible in the images. Sighted on a metal handrail at Tidbinbilla's Sanctuary and constantly on the move.
Hi TimL, beautiful pictures and I think that's a really good ID. Check out the images at the site below. Cheers Jon https://www.antweb.org/specimenImages.do?name=casent0217886