Messorus,
That Gigantiops picture is awesome! what a beautiful ant species.
G
Pseudomyrmex are ants that just have very small colonies, smaller than Gigantiops destructor and so on.
The keeping is very simple and the main problem is finding a good nest for them.
Pseudomyrmex mostly live in grass, in the empty dry pipes and not even in the thick ones. The main problem with that is that mould kills them and such small nests can mould very fast.
Some Pseudomyrmex spec. don´t even reach 100 ants per colony!
They can live in very dry old wood, too, but in very thin sticks.
They mostly eat sugar but like evry ant need proteins in form of little insects.
By the way those ants are very interesting. They can see very well and hunt good for small insects.
They can be kept with other ants of Brazil.
PS: They live in the same locations as Cephalotes and other small ants, they can be kept together. Just wanted to mention because those are very nice ants, too.