The whole argument for why the ants shouldn’t be eradicated keeps being eroded. They are pretty much doing most of the things people are afraid they would do. In this book, they got aggressive about acting just to expand and they also wipe out races the eldest doesn’t like. They treat monsters like monsters but what to be treated differently. It’s starting to be where the ants do something and the story justifies by making the creatures they so it to bad enough or wrong in some way that makes it okay.
TLDR; The ants are starting to act like the monstrous ants people are afraid of but with plot armor.