Only one gene determines whether an ant will become a queen or a worker
One gene, one queen in the ant world - life science news

The protein insulin-like peptide 2 (ILP2) has been found to be made in large quantities only in queens, not in workers, in ant colonies. ILP2 is synthesized in 12 to 15 brain cells only, and turns an ant into an egg-laying machine. Injections of ILP2 in ants from colonies where there is no queen, but where each individual undergoes a cycle of reproduction by cloning and brood care, induce queen-like characteristics, such as slightly bigger body size, and start egg laying. Good quality nutrition stimulates the formation of ILP2, which seems to suggest that the evolution of sociality in insects may have started with imbalanced food distribution among colony members.

Read the full story: Johannes Gutenberg Universität Mainz
Scientific publication: Science