Zombie migration and no respawn in sandbox

[1ostcat]

I'm in early February of the first year of a standard sandbox game where the zombie population is 1.1 but the Respawn Hours is set to 0.

I assumed this meant no respawns would occur.

I'm based up in the gated community of Riverside, and I'd previously completely cleared the area around the factory, storage facility, and trailer park north of Riverside.

I've been making forays into the country club for a couple of in-game months, and have the majority of the areas around buildings and paths clear.

I've driven back and forth along those roads nearly every day for in-game months seeing only an occasional zombie or two wander towards the roads.

Then, a couple of in-game nights ago, as I was leaving the gas station near the trailer park north of Riverside, I saw a handful of zombies making their way across the road. I ran over to engage them and realized it was an entire horde...dozens of zombies.

I killed as many as I could by the light of my flashlight, until I got too tired to swing my machete effectively. A couple of days later I came back and finished them off, but around 3pm I was about to leave and another horde wandered out of the trees between the trailer park and the gas station.

This time there were around 300 zombies (I checked my kill count before and after).

I'm completely happy if those hordes wandered in from elsewhere, because that's the kind of behavior I want. But I'd not be happy if those were just newly spawned zombies I had to spend hours and resources killing. I haven't seen a single zombie around my base for in-game months, so it was kind of weird to see so many appear in places I visit fairly regularly.

TL:DR

Is it normal for there to be wandering hordes of 300+ zombies 6 months into a game, or did I mess something up with the respawn settings. I only set Respawn Hours to 0, but didn't touch Respawn Unseen Hours or Respawn Multiplier.

[Chris!!]

Wiki states that setting respawn hours to zero should prevent zombies from respawning, so it should just be migrating zombies.

[Jambie Lionheart]

What day did you set peak population too?

and if you have migration on then yes, but it also depends on your group settings. What is group size set to? When leaders migrate they tend to drag the rest of the horde with them.

[Issiah Freeman]

If you set peak population to hit on a day later than immediately, zombies will still spawn until the day you set peak population to be hit.

So if you set peak population to be reached 7 days after start, then zombies will continue to spawn until day 7, which after no zombies should spawn and it will only be left with migrating ones.

This causes it to seem like they're respawning when in reality it just hasn't fully populated the map with the "initial" zombies yet


Edit: To fix this problem, set "Population Peak Day" to 1 and it will cause zombie population to be max on day 1. (No more seeming "respawn" of zombies)