Written from years of experience keeping this species. I recommend keeping them in at least a partially bioactive environment
When founding, I've found much like other ants they need a small space to start their nest in, unlike many other ants whom nest underground Polyrhachis dives do not, they require areas above ground in which they can weave and build a nest. I call this their scaffolding.
I have found when they are young they will stay very low to the ground, possibly starting from a fallen branch within a Bush, as they grow, they begin to expand upwards and outwards towards their preferred spot of a low level Bush, unlike some Weaver Ants that prefer the canopy.
We find a bioactive environment offers these opportunities really well. With plants growing with the nest they will continue to grow and expand. I find ferns look really good but also offer great debis for nesting materials especially after a trim, we also find dried sphagnum moss flakes and other small dry items make great nests aswell.
Offering a randomised patten of stick and branches also work well as a scaffolding, try to aviod leaving large gaps between branches, they will aviod nesting in these spaces, looking for the easier areas.
Keep in a warm and humid environment, preferably on soil, our Ants on a Rock Substrate booster is great for this. Aviod sand areas unless very damp. Ponds and water are not an issue, they have a great ability to swim and walk out of the water if they fall in.
When selecting your Enclosure, it's good to plan ahead. We advise when they are in founding to 100 worker stage to keep them in a small manageable unit, moving them to a large unit or tank.
Main thing to think about is expandability, Polyrhachis grow into very large colonies numbering in the thousands.
Height is also very important, as mentioned earlier they will expand upwards, taking up a lot space as they do so. They will nest right up against the Ants on a Rock Barrier mix but will not cross it. We highly advise you use this barrier mix for these Ants and environment.
Polyrhachis dives can be very hungry, feed them a diet of Pre killed insects and and Carbohydrates from Sugars or Candy mix, they will also take jelly pots when in larger stages. They can take down small prey items but it can take some time to dispatch larger prey so we wouldn't recommend this. Feed them regularly and with plenty, they require protein for the larva to produce their silk. Hungry larva means no nest growth.
Polyrhachis are highly aggressive especially in larger colonies, this being said cohabitation is possible with isopods, springtails, many types of beetles and other inverts, ensure they have lots of space and hides to aviod each other if they need to.
Polyrhachis dives are very aggressive, they can bite and spray acid, this does hurt but does not pose any kind of health risk, they will be very aggressive towards each other, often culling the weaker workers and and intruders.
Humidity requirements: 75 – 99% •
Temperature requirements: 26 – 30 °C
Suggested housing: Glass, soil.
Nutrition: Sugars from honey or Ants on a Rock Candy Mix. Protein from insect sources such as Waxworms, Mealworms or Dubia Roaches.
Colony size: 1-10,000 when mature
Polygyne: More than one Queen per colony