Minecraft wiki entry for Villager_trading_hall, associated text: Once a villager is discarded, it is up to the player to do what they want with them. The most common thing to do is move the discarded villagers into one area, where they are killed by whatever means suits the player. It is not recommended to kill them manually, because that will lower the player's popularity, and if the popularity gets too low, any iron golems of that village become hostile toward that player. An alternative to killing the discarded villagers is to store them for an iron golem farm, put them into a village, or put them to work in farms and breeders.