It did not take long for adventurers to bring back a case full of worms. They used them as bait to catch fish. On exposure to Goblin Cave's mana, however... they did not quite liquify, but it was very clear even the moderately higher ambient mana within the cave was fatal to them. It still gave them a polyhedra of bronze.

It had to fashion a crude — and cheap — mana-sealing enclosure. This involved trace amounts of mithril, which it attempted to hide as well as it could. It was exhausted of interactions about how valuable everything it made was, and it was hoping to put off that one as long as possible. It ended up with a thin, quartz-walled box that entirely muffled its mana flow when closed, and heavily damped it when open. Then it handed the box off to some adventurers with instructions to place worms in it.

While it had been doing that, it had also been contemplating a spawn template. Worms were long and tubular, fleshy, and it could vaguely try to feel out for that kind of physical structure. Earth aligned, or dark. Some kind of tunnelling ability, or maybe earth-eating.

But the time the adventurers came back with a second batch of worms, it had determined it:

New creature template unlocked: [Giant Earthworm]! Giant Earthworm annelids (tier 0, earth) An enormous mutant earthworm. Eats out tunnels beneath the earth. Has the ability to slowly eat through rock.

So there was a system construct. Although its own giant earthworm — roughly as big around as an adventurer, and twice as long as an adventurer was tall — was very clearly different from the non-system-connected earthworms. It did specify 'Giant'. But why not, say, [Giant] [Earthworm]? And the category... an entire spawn category of worms?

What was of more immediate concern was what it was to do with the worms. It had them in a sealed box, but even just looking into it was harmful to the worms inside. It sat and looked at the exterior of the box. This was where its practice with imaging tubes came in handy, it supposed. It reconstructed a new kind of mana-warding material, this one somewhat slapdash made mostly out of coreglass and serpent obsidian, forming a deep, dark-tinged glass that was still opaque to mana, and it aimed an imaging tube at it to focus the contents. A window looking into a churning pile of worms.

The adventurers said that it could feed the worms nearly anything, really. Rotten food, grasses, plants, dirt. It tried some dewdrop sprouts, but... like everything other mob it spawned, they were infused with its own mana too. It still tried, getting its invisible servant to open the box and dump in the fruiting body, and it was difficult to say just from looking for a few hours whether the mana influx was poisoning them or not.

Worms. It also asked for 'ants', but those were apparently harder to collect in meaningful quantities. They were parts of larger colonies and required involved digging to extract. The real concern was, if these were creatures that mana was somehow inimical to, how would it go about observing and tending to them over the long term? Everything it did radiated mana. The implication, in fact, seemed to be that a worm that acclimated to mana, however that happened, grew into a [Giant Earthworm]. And perhaps gained a system connection? Its giant earthworm had a whole 3 mana, and a skill, [Acid Ooze], that it could spend it on to slowly dissolve rock. The earthworms within its box had, as far as any of the adventurers could say, no such skill. It had no skills.

It would continue feeding some worms its mana-infused fungi, and see if that killed or mutated them. It would separate others, and try to... make a larger mana void, and attempt to grow non-magical fungi? It had no clue what the habitat of an earthworm was, aside from 'in soil'. It had never been very good at spawning soil; too many organic compounds.

It was interesting. This was the closest it had seen to something outside the system, and it was observing what that meant: no skills. No spells. No stat block. No mana. No experience. No levels. No souls. A thing entirely of physical matter, without any reflection in system-space. Such a thing was an impossiblity within a dungeon. Conceptually, Goblin Cave could imagine a spawn template that manifested a mob with zero mana, but in practice every mob it had ever unlocked had at least one point of mana and one mana-using skill or spell. The resonances... spawn templates just wouldn't balance. As mana went to zero, other factors shot off to infinity, so in practice there were no stable spawns of zero-mana mobs. That invited the fascinating question of whatever negative mana did to influence a spawn pattern — a way of connecting what it was doing now with the heretofore extremely abstract and unclear question that surveyor-adventurer had asked.

So, worms. It dug out a fresh cave off from its third floor, gave it a thick layer of dirt, and then reinforced the rock around it, threading through the mana-sealing lattice of serpent obsidian and orichalcum, and finally capped it off with a backwards-facing mana lock. A sealed chamber that grew hazy and then turned into a void within it. It had its invisible servant toss some of the worms through the lock, and observed them squirming on the dirt for a while before slowly burrowing their way into it. It had no way to tell if they would survive, much less reproduce. It supposed it could tell adventurers to dig for worms in there periodically.

Then, ants. One enterprising adventurer dug out a whole anthill, and on being provided another mana-sealing box dumped the whole swarming mess into its corridors. They asked for a small cube of silver, which, Goblin Cave supposed it had no reason to reject. It did appreciate the ants. It had to dig out a second dirt-filled chamber for the ants, this one with a leakier seal so it could spawn some fungi within. The earthworms may have been able to eat just the dirt (somehow), but the ants — apparently — absolutely required some food. The ants at least crawled up to the surface, so it could observe them as they meandered across the cave and found the various fungi. It was difficult to say whether the mana exposure from its weedy, half-starved fungi was enougle to poison the ants. Making ecological cycles was one thing, but making ecological cycles without anything that contained mana was beyond impossible.

Then another adventurer showed up with another box of ants. These were "the biting kind", apparently. Goblin Cave obligingly took them and handed over some bronze, and had to make a third dirt chamber. Apparently different ant colonies did not cohabitate well. Seeing two things with such slight differences... the difference between a [Goblin] and a [Fierce Goblin] was fairly paltry: a handful of stat points, a slight change in the color of their tusks. The biting ants had more of a red-brown color, with a tinge of yellow, compared to the brown-black of the non-biting ants. What made them different? Why were they different?

New creature template unlocked: [Giant Ant]! Giant Ant arthropods (tier 0, earth) A giant ant. Its pincers are reinforced with earth-aligned mana to allow it to eat [Stonefungus].

It was also able to discern a similar system-analogue mob. As opposed to non-system ants, which only existed in what was apparently a complex hive structure driven mostly by food scarcity, it had no problem spawning a single giant ant and leaving it to sit in its halls and passively eat nothing but its mana.

It also, humorously, expanded its hallway of creatures, adding instances of its two new categories to the list. That hallway might get very long very quickly, if each new thing collected from the outside did in fact have a system analogue.

All this gave it a new angle on what system-space was doing. If the mobs were system-analogues of a purely-physical creature, then the distinctions between them could say something about the intent of the system. Both mobs were much larger than their physical counterparts — adventurer-sized — as well as more aggressive, or at least, more easily turned towards aggression. And they both had descriptions that implied they were mana-mutants. And they both yielded experience when killed.

That was the fulcrum by which the entire system operated. Squash an ant, and you had squashed an ant, for no reason beyond your own desires. Kill a [Giant Ant], and the system reached down, catalyzing a transduction from mana to experience. Rewarding the killer. Kill more, and more power will be yours. Ants ate fungi to survive, and the mana clinging to its fruiting bodies was, perhaps, a poison to them. If a [Giant Ant] killed a [Deathcap] — it would gain experience (well, outside of the context of a dungeon. Goblin Cave supposed it could try oversouling a giant ant to see if it would begin to gain experience, but... this was a tangent) and it could level up. It was an incentive for a creature to glut itself on death, kill far beyond its need for food.

It lined up with its own existence: a killing hall, a place that existed only to produce death. A place full of simulacra bodies that were born only to die. The world the system seemed to strive towards was a world of ceaseless death: the victors reaping experience from the fallen, and being reaped again in turn. Transducing mana over and over into experience, until...?

It had yet to determine what experience eventually flowed out to. There were many things unaccounted for in its conceptualizations of the world, but what it had seen so far did not look good. Just kill? Plenty of things killed each other for necessary purposes already; Goblin Cave didn't see much use in adding even more incentive.