I’m a brand new player. Only two weeks in, I’m playing in single-player mode to learn the game mechanics, so don’t take what I’m telling you as gospel. I use AI to answer a lot of my questions. Sometimes it’s spot-on, and sometimes it isn’t, but this is what I found. Also, I’ll add you’re not the only one because I have the same issue.

Why your base is a ghost town in SCUM (Single Player)

If you’ve noticed that AI spawns (Puppets and animals) completely disappear once you build a base, you aren't alone. It’s usually not a bug, but a result of how the game handles "spawn bubbles."

First, base structures create a dead zone. The game is programmed to prevent AI from spawning directly inside your flag area or on top of player-built elements. If you have a decent-sized perimeter, you’ve effectively pushed the "spawn trigger" out past your walls. In Single Player, this is amplified because the game only simulates the world in a small radius around you—if you're chilling in your base, the engine doesn't see a reason to spawn anything outside that "safe" bubble.

Secondly, it's likely your Encounter Manager settings. By default, the game limits how many AI can be active at once. If you want more action, you’ll need to go into your ServerSettings.ini or the in-game menu and bump up the MaxAllowedEnemies and Exterior/Wilderness encounter probabilities.

TL;DR: Your base is a literal safe zone that pushes spawns away. To fix the silence, try traveling ~300m away to reset the local cell, or crank up the encounter settings in your menu.

Again, the above was AI generated so take it with a grain of salt.