Spawns in bases

I built a base on an island near the Sentinels. 1 Shaleback and 3 babies spawn on said island. I have a small house and most of the island is walled in, I also completely foundationed (is that a word?) the entire area inside the walls so there are no spots that are not paved. The Shaleback and babies still keep spawning inside my base, but all the trees and rocks have stopped spawning, so I know the game has noticed me there. How are you supposed to make decent bases if things keep spawning inside them?

By not stealing the homes of innocent critters.
These shalebacks are just trying to live in peace and then you come along and try to evict them. I’m glad they aren’t giving up so easily.