Large ant harassing wasps and bees.

Large, about 18mm.
7m above ground in dead part of Ficus sycamorus amongst a cluster of Carpenter Bee entrances, shared by Mason Wasps. The single ant was generally making a niusance of itself, lunging at wasps in the burrows and inspecting the Carpenter Bees at work.
4th pic shows this ant, face to face with a more conventionally sized ant and a male carpenter bee in background.