After uninstalling all my mods that have anything to do with spawns I've found that the vanilla version of Kenshi does the depopulate thing as well.

I set squad numbers slider to max,squad size to 2 and max number of nests spawn then went for a journey into the fog islands.Coming close to nests was depopulating them with the message that they were destroyed.

Kenshi most likely has a despawn *feature* somewhere I'm not aware of and it likely kicks in when a cedrtain number of NPCs are reached .... culling new NPCs as the player loads/generates areas,for performance.

Weird. I'm getting back into the game at present and re-adding mods slowly (so far, just my raptor meat and storage mods), so I haven't had a chance to investigate this yet.

WHat I mean is .. the camps depopulate and getting the message ""xxxxx camp 0xx has been detroyed"" or something similar in a spam fashion.

The camps seem to despawn when the player gets close to them (possibly into the same biome).This is an issue I'm seeing with all mods that spawn camps at the moment.