Instead of a sugars-protein system, I think different ants and colonies should harvest and consume different types of food. Wood and Black ants should only have access to "meat" and aphids, and that in the Ereptor colony, different castes can harvest different types of food. Only workers of this species can harvest seeds for example. If this does have an impact on gameplay in Freeplay, perhaps Black and Wood ants get more food than usual from harvesting corpses and seafood. I think this would make the game more realistic without changing up lots of levels and food counts.
Ants are beautiful,
but if fooled around with,
can be deadly.