Minecraft wiki entry for Villager, associated text: A census is periodically taken to determine the current population of the village. All villagers within the horizontal boundary of the village and 5 vertical blocks‌[Java Edition only] of the center are counted as part of the population to determine if continued villager mating is allowed. However, any villager within the horizontal boundary of the village and the spherical boundary of the village attempts to enter mating mode as long as there is at least one villager within the boundary. If two villagers simultaneously enter mating mode while they are close to one another, they breed and produce a child. The appearance is determined by the biome where the breeding occurs in Bedrock Edition.[1] In Java Edition, the appearance is randomly determined by either the biome type of the parents or by the biome where the breeding occurred.