A small mod that adds the Anti-Mob Beacon, a Block that stops mobs from spawning in a radius around it. Did you ever want to create a build in the dark but were too scared of monsters running all over? Before this mod you would probably have spammed string all over to stop the spawning, taking several hours for bigger builds. But worry no more, the Anti-Mob Beacon will save you from this tedious work.
You only need to place a single Anti-Mob Beacon, add some water to finalize the block and fill it with lava. The more lava, the higher the range in which no more mobs are spawning.