I estimate the size at 1.5cm, only one caste was observed, and they were very aggressive, raising their backs at provocation, also, one bit me on the foot because I was in her way.
Interestingly their foraging path crossed over the top of a large gate, when the gate opened for cars the ants would queue up at each side, confused, and then resume their journey when the gate closed.
Lots of interesting ants in this part of the world, in 2 minutes outdoors you can find 5 different types without even trying.
Sorry about the picture quality, these are from a camera phone.












