In an effort to spice things up a bit, I made the decision to inject cave flies into C12DS. After all, the majority of the population was centered in that one specific corner of the map, I suppose because the sunflower is there?
It seems all I succeeded in doing was making them extra miserable. But at least it's gotten them moving, in one direction or the other... so hopefully given a bit of time, they'll start to spread out.