https://i.imgur.com/4utn2Bn.png

I've got a couple biters wandering around my defenseless Vulcanus base and they're just...not hostile.

I don't know if it's because there's no pollution, but given vanilla biter eggs will hatch and attack on space platforms, I'm guessing it's a bug with the dangerous biter eggs from voidcraft. As you can see, they're right next to the voidworks making biter eggs, and I've got an inserter that's supposed to immediately burn the dangerous eggs. I'm guessing the inserter was too slow on exactly 2 occasions (maybe because it was moving spoilage?).

Ok, it gets even weirder. A few minutes after noticing them, they're both just...gone. I don't see any corpses, and I didn't have any defenses set up anywhere on the planet. My tank doesn't even have a laser defense because it's Vulcanus and demolishers are immune.

I did an experiment where I hatched a dangerous egg on Nauvis, and as long as nothing was around provoking it (like laser turrets), it just wandered around. I've gotta wait a bit before the non-dangerous eggs hatch and see if they do the same thing.

The second one is probably just the biters despawning. That happens.

I'm not sure if there is anything that I can do about this. You can see the code for dangerous eggs in dangerous.lua: it's just the regular eggs, only with a different name, tinted red, with a much faster spoilage timer. The actual code that generates the biters is an exact copy of the base game's.

After some experimenting I think it's just vanilla biter behavior. The biters I saw were not near anything they're normally hostile to, and they weren't being attracted by pollution. They ignore stuff that doesn't bother them until they're mad, and with no defenses and no pollution they didn't have anything to get mad about.

[facepalm] And it's not even the dangerous biter eggs that were hatching on Vulcanus. It was the regular ones spoiling because my circuit conditions were out of sync with each other; the EM plant wanted to make 100 producitivity module 3s, and the circuit telling the voidworks to turn on/off wanted it to make 150 modules, so it was feeding the EM plant an egg and the EM plant was not using it.