Nest: workers of different sizes and colouration (differing degrees of orange and black)
Foraging around base of tree on sandy compacted soil
Strobe ant. There turned out to be many on this tree; since a group of weaver ants was also on this tree, I am guessing that some mimicry is involved.
Here is a video of it exhibiting very jittery movements: https://www.youtube.com/watch?v=z63wH0H_FBc&feature=youtu.be
Another such ant on the same tree was https://www.inaturalist.org/observations/2757897
nesting inside a Hydnophytum ant-plant