what about making only the large ants capable of digging?
then add cave_adapt and size to the miners with lower skill gains in fighting with maybe weaker chitin
can there be castes that require meat and castes that require plants? fire ants require meat and leaf cutters require fungi kind of thing
could they farm aphids? well we have honeydew beetles already..
could they get mutagens to change castes, maybe in a circle instead of how the dwarves have it
maybe for magic they can 'adapt' into having spider or scorpion traits? poison, leach life, scales, a tail, webs or large pincers. or maybe use the fallen enemies to become better, dwarves for thick skin, elves for agility, orcs for strength, warlocks for willpower or something, automatons for longer life and no food/water etc
can they have babies like someone else suggested for kobolds? have the babies referred to eggs? with the children as larvae
might work to have the babies transform into a creature classified as a egg then 'hatch' to transform into a larvae and to 'molt' into a full ant, such as have the transform last for 2 seasons then 2 seasons for larvae which finally leaves the untransformed ant to become an adult ant
could the ants have a workshop that transforms an ant into a creature that's immobile with milking?
honey pot ants