[quote]-Formican (Ants change the land, giant ants cause instability and extinction ensues)[/quote]
Keep in mind that Mammoth Ants are herbivorous and only exist in the Deepwood's heartlands. The Bull Ants are very aggressive and may have caused some extinctions, but they only live in the Deepwood heartlands too, so do all giant ants.
No giant ants live beyond the Deepwood's heartlands. All other ants live wherever.