Fred Adler at the University of Utah described how ants actually hate each other but will work together:
In what researchers describe as “un-peaceful coexistence,” multiple ant species stake out the same territory and compete for the same food, but no single species wins out since some are better at finding resources and others better at guarding them. ...
The take-away message is not that utopian co-existence is possible, since after all, said Adler, “these species hate each other.” It is more about understanding the natural limits of organisms: No single species wins every time, because it is impossible to be well adapted to do everything. From an evolutionary perspective, he explained, “there are limits to how well you can design something.”
http://www.livescience.com/animalworld/070222_ants_coexist.html - via A Welsh View