i think it's mostly a matter of min/max ratio to the colony size/type of ant. But being outside those is not necessarily a negative, it's just maybe not optimal.
"too much" space is just really wasted personal space of your own, if they have more than they want to use, and so just ignore.
"too little" and they will basically be living in all nest from their POV. Their behavior will be largely undifferentiated to observe anywhere in the setup. But not enough space is just the limiting factor in a lot of things we do.
One thing i have noticed in a recent change i had. Distance seems to have played a significant factor. The nest was connected by tube about 9" long. Now it is direct, maybe 1/2" of tube/wall from in nest to "out world." Which it for sure is not to them post move.
But the large outworld (9x5x5) connected about as far from the nest exit as it could be(3.5" maybe) and another 2" of tube. It's treated very different by the ants.
They started at 27 in a THA mini hearth + fallen fortress outworld(4x4x4) on 9" of tube, and the 9x5x5 on it (direct, maybe 1/2 tube).
Over time the 4x4 started being treated as nest a little, and after this move it's had larvae put on the apple slice(not permanently but at times), the main seed stock added near the nest proper entrance, and a large % of the ants live out in it rather than the several mostly empty chambers of the new nest.
The 9x5x5 continues to be somewhere only a handful of the nest will go.
I got another on the way, and the last as it's all i got room for. 11wx8dx9h(something close to that).
their count recently was at 150-175. Maybe 30 ants max will go into the large outworld during high busy times. Which is just their own schedule not related to me adding forage.
I do keep a water station in both outworlds. But only put apple and insect in the smaller one to keep the large space dryer.
Edited by Full_Frontal_Yeti, June 28 2023 - 8:29 PM.