My favorite colony at the moment is Pheidole ceres. However, of all the species I have kept, I think I actually enjoyed P. megacephala the most. Sadly, that colony overstepped its bounds (literally) and had to go.
Why didn't you just cut the worker population?
That's a good question. At that point, they had actually managed to relocate their entire colony of thousands into my tropical vivarium overnight. It's a long story, but, essentially, the way the tank was situated would have made it extremely difficult to extract them without harming the queens.
Also, not long before this incident, they had literally been recruiting soldiers to chew through the hot glue in the lid, and they somehow managed to traverse vaseline immediately after I would apply it. Anyway, very difficult ants to contain. I did not feel right keeping an exotic species that escaped continually, even if their chance of establishment was negligible given local climate.
Edited by Myrmicinae, July 27 2015 - 8:56 PM.