Minecraft wiki entry for Village, associated text: Job site blocks are blocks such as grindstones, smithing tables, and lecterns, which are used by villagers. Villagers with the corresponding professions spend their time in front of their job site block, except for nitwits, baby villagers and unemployed villagers (villagers without profession overlays). Upon claiming a job site block, green particles appear above both the villager and the job site block, and the villager takes up the profession of the job site block if unemployed. Villagers that have already been traded with can claim only job site blocks related to their profession. Employed villagers that are not linked to a job site block are unable to restock their trades. Villagers cannot link to a job site block that has already been claimed by another villager. There are thirteen job site blocks in the game, each linking to their respective villager profession.