Over at The Register:
Ants can grow from larvae into many different bodily types, including soldiers, workers, or queens, depending on how they are fed and raised within the colony. The team analyzed the genetic structure of the supersoldiers and found the mechanism for their growth, a juvenile hormone.
When the team applied the hormone to larvae from these species, they found it easy to create the super soldiers. The surprise came when they tried a similar technique with species that don’t normally produce such heavy soldiers. They found that they could still create supersoldiers in these species, by activating genotypes from a common ancestor of the pheidole genus.
Ah, meat and bread for the science fiction writer. Sort of makes me think about Pournelle and Niven's The Mote in God's Eye. It also makes me think about a battle version of the Brumallians in Hilldiggers.