We've taken a snotling camp, kept the fires and farmland, but destroyed everything else. They didn't seem to spawn there at all afterwards, so I rebuilt it as one of our outer camps and it serves us quite nicely now. The snots rarely spawn close to perimeter (where it's located is a narrow land bridge between a forest/plains biome), tending to spawn more towards the coasts, East and West. It really felt like once we kicked them out, they stayed out. The mosquitoes keep spawning close, sometimes inside the camp though. So if you plan to keep it, watch out for that.