Due to some recent topics/posts about fusing ant colonies, I just want to post some information: Ant colony fusion is nearly impossible.
You've probably watched youtube videos on parasitic ant queens, brood raiding ant queens, etc, but those are specialized species. Even then the enslaved workers may rebel! If that is what happens with a specialized parasitic species, think about what happens with a normal ant colony.
For those who think they know people who can fuse ant colonies, they're most likely wrong. Those people also may have confused a person who rears parasitic ants with a person who "magically" can fuse a colony of any ant species. If that could happen, no ant wars would occur!
Even introducing an unrelated (colony wise) worker to a queen of the same species can also be terrible. The few times that that may work is when the queen receiving the worker is polygynous or a supercolony species.
With that being said, keep your ants separate!