In my world, I've cleared out an entire chunk, from bedrock to about 90 (ground level). It is a slime chunk, and slimes are spawning in the bottom. At level 40, I constructed several hostile mob spawning pads. They are dark, and have a large enough area for mobs to spawn. But the strange thing is, they're not spawning at all. During construction of the pads, there were a couple of skeletons, zombies, and a creeper, but nothing near what you'd expect from an entire empty chunk. There are no slimes preventing spawning, and I've AFK'd for quite a while beyond 24 blocks from the pads.
So my question is, do normal hostile mobs (zombies, etc) not spawn in slime chunks?
Best Answer
Yes other mobs will spawn in a slime chunk. The thing that is affecting your spawn rates are the chunks surrounding your spawning chunk. If memory serves there is a sphere surrounding the player. 128 blocks in all directions. Inside of which mobs can spawn. So what is going on here. Is that the mobs you are wanting. Spawn elsewhere. Light up caves in the surrounding area. Or strip mine the whole area. (the method I use.) There is a useful image on the minecraft wiki page regarding spawning. If I were slightly more tech savy I would have provided it.
Happy crafting.