Ants are one of the most numerically and ecologically dominant groups of terrestrial organisms on the planet. To understand the factors that have shaped their ecological and evolutionary success, it is important to consider not only their evolutionary history and the time frames involved, but how mutualisms and associations ants have with other insects, plants and bacteria have contributed. Through a combination of methods in evolution and ecology, including molecular systematics, comparative genomics, diversification analyses, biogeographic range reconstruction, diet experiments and microbiome pyrosequencing, we are beginning to understand the importance of both the evolutionary and ecological timescales on ant diversity.