Yeah this is an issue, spawns happen despite workbench/fires being placed. I've stopped them, by making stone walls, and stone floors for the entire compound. I'll remove the stones to make gardens and at each corner and middle I have the large bonfires going on stone pillars with workbenches underneath. Nothing has spawned inside my compound since I did that. It will cost much stone though.

i dont care for the stone but it will also look ugly as hell. I dont want stone floors in the parts of the castle where i breed lox and such :(