Minecraft wiki entry for Village, associated text: When the first villager links to a bed a village of size 65×25×65 blocks is created, centered on the pillow of that bed. The boundaries, and consequently the center (which is important because it defines where cats and iron golems can spawn), may change as other villagers link or unlink from point of interest (POI) blocks. When the boundaries change the center usually shifts to the location of POI block near the midpoint between the farthest out POI in each direction. In naturally generated villages there is usually a bell near the village center, but aside from that bells have no special role distinct from other POI in how the game defines and manages the village center and boundaries.