"Forest trails would be the result of animal movement, and it makes sense for these to be connected to the gaps in cliffs because that's where they can get through" - Earendel, FFF #401

Factorio Friday Facts #401 revamped Nauvis terrain generation to produce naturally occurring paths that can be understood as the natural migration routes of Nauvisian wildlife. This mod makes that a reality, adding migrating (passive?) biter migrations that travel along these natural world-generation structures.

Migration units are given long, snaky territories to mimic wildlife migration routes, and have been given the ability to repopulate nearby territories when a migration unit is broken. Together, this should feel like packs of wildlife traveling through the wilderness.

This mod changes Nauvis from a planet where you build an entire perimeter defense, into one where you instead build concentrated defensive structures at useful chokepoints like cliff ridges and isthmuses. Terrain is now an emphasized part of defense.

This mod is for you if:

• You're looking to experience Nauvis in a new way
• You're a Factorio veteran looking to skip the perimeter defense and get off Nauvis fast (especially if you're using a modpack with many planets!)
• You're a new player looking to engage with biters when you feel ready to. You don't have to fight biters until you want to expand your factory into their territories

This mod can also recontextualize Nauvis, into a true starter planet, giving you tastes of all the elements of Factorio gameplay, rather than (in my opinion) being balanced toward high-consequence base defense. No longer does a single breach along a full perimeter risk losing your entire factory! Particularly useful if you're caught off-planet and can't quickly make it back.

Recommended settings & companion mods

Consider changing nest expansion to either 0 or very low. Also consider adjusting nest prevalence to your taste.

Consider adding:
- Eye for an Eye (Fixed)
- Some mod that changes pollution mechanics?

Credits

Specific shoutout to Larmantine and their mod Demolisher Rework. This mod takes and moderately adapts their code for the migration repopulation and territory coloration features.

Performance

Emphasis has been given to making this mod performant, and I've tested it a fair amount. I have not noticed any lag spikes or other difficulties running the game at very high speed and map exploration.

Statement on generative AI

I have experience with coding but not Lua, and am just getting started with Factorio modding. I used Claude for many of the more complicated implementations and as a learning guide. Nothing besides code was made with generative AI. There may be some small code redundancies, but I've cleaned it up as I could

Please let me know if you have ideas for improvements!