When in a small and dark room (area something like 4x4 blocks), zombies spawn in that room.

When in a room that's dark with a small amount of space, zombies spawn in that room.

What I expected to happen was...: that zombies wouldn't spawn there.

What actually happened was...: zombies spawned in that room.

Steps to Reproduce:
1. Be in a dark room (area about 4x4 blocks)
2. Zombies spawn in that room.