How large could a hive of giant animals be?

Question

I'm thinking about possible ecological niches for giant ants and the like, but for the purpose of this question the actual building plan (insectoid or whatnot) is (I think) not relevant. The question is, how large a hive could meaningfully exist if the individual animals are rather large?

Let's assume the following for our Hunoants (huge not-ants):

• 70-100 kg per animal (comparable to a boar, I think)
• cold blooded
• egg laying with one or a few queens per hive
• fairly elaborate nurturing of the young, including feeding (either like mammals or like honey bees)
• terrestrial
• individual animals grow to several years, the queens even longer
• lives in the tropics, no real problem due to the seasons
• build large nests or burrows
• In my imaginations the hunoants are rather slow and methodical and not nimble hunters

My thinking for a possible ecological niche would be (again, similar to ants):

• gathers fruits
• possibly uses leafy plant matter and grass via intermediary step, like the fungal gardens leafcutter ants cultivate (no ruminant digestive system, that would make them too cumbersome)
• gathers carrion
• actively hunts animals that are bad at running away (large snake digesting a tapir or very small animals), preferably herbivores
• uses superior numbers and stinky poisons to scare larger animals away from carrion
• may use same tactics to scare away other herbivores
• individual hunoants can fall prey to many large predators, however they seldom are alone

When the hive does not move, it means the individual animals need to bring everything they forage back, limiting the size of the territory (due to the time it takes and at some point carrying to food back to the nest burns more calories than the food is worth). So what would be a ballpark estimate for how large a hive could be? To be really hive like, we'd want thousands of animals, meaning 10-50 tons of animal. How much area is needed to support that much animal-biomass?

The question basically hinges on what a plausible carrying capacity (animals/ha) and what a plausible radius of action is for animals like these. I'm not asking for a huge research effort, but please have some backing for the numbers you use

Note that some of the bullet points above are meant to make larger hives viable:

• the hunoants effectivly manage their area by driving out competition
• cold blooded animals need less food

Answer 1

According to this article on high stock density grazing, your upper bound on hive density is going to be around 10,000 pounds of animal live-weight per acre. Let's round it to 1 kg per square meter so that everything is nice and metric.

Edit: I realize that relating these creatures to grazing animals in not exactly a fair comparison, but it should be noted that I'm comparing them to grazing animals in non-tropical regions and tropical regions actually have an even more concentrated biomass which would likely support an even greater population density

Hive animals are actually incredibly efficient at gathering food, and it's not at all unreasonable that they can gather everything within a quarter day's travel of the hive.

A slow cattle drive would travel about 16 km, so call it a 4 km radius on the hive and you've got yourself an upper bound of about 67 million kgs of Hunoants which is around 600,000 individual creatures.

Also to be kept in mind is that ants have been known to herd aphids, so it's entirely within reason that this essentially mindless hive creature has essentially domesticated some even more mindless creature to use as food.

Answer 2

Keepers of the forest.

Let us say these ants live in an area with warm climate and rainfall. Every single plant that grows in the forest can potentially be food, because the fungal symbiont of these creatures can break down cellulose.

The ants go out into the forest, each carrying a lump of feces. Sometimes they carry a dead nest mate. When they find a suitable piece of greenery, either fallen or to cut loose from a tree or bush, they set down the feces and take the vegetable matter.

The nest underlies the entirety of the forest, extending from ocean to ocean. The nest has hundred of entrances. It is thousands of square kilometers. These farmers are keepers of the forest, clearing away dead matter and enriching the soil. They really are servants of their fungus, performing the role that fungi do generally but on a macroscopic scale.