Minecraft wiki entry for Beginner%27s_guide, associated text: Before 1.18, more light is needed prevent monster spawning: A single torch prevents monster spawns completely within a 7 block range (barring obstructions), and reduces them for about the same distance past that. That range is in taxicab distance, with each square east, west, north south, up and down counting independently. Accordingly, the safe zone only runs 3 spaces or so diagonally, and steps up or down can shorten it further. Even outside the safe zone, having some light sharply reduces the chance of monsters spawning (depending on how much light), but it's better to use enough torches to keep your whole home well-lit. If you have extra torches after that, try to light some space outside your home (or at least the entrance) too, to push back the area where monsters are likely to spawn.