Minecraft wiki entry for End_survival, associated text: Since almost everything works the same in the End as it does in the Overworld, the player can then set up the farms they would in the Overworld without great difficulty, once the animals or villagers required for it are in place. (Beds explode if a player tries to sleep in them, but villagers follow a normal day-night cycle in the nether and end, and sleep in beds without issues, allowing for Iron farms and artificial villages to function normally). Villagers will still trade Glass, Glowstone, Redstone Dust, Lapis Lazuli, Bottle o' Enchanting, Bows and Arrows, Armor, Tools, Enchanted Books, Stone variants, Block of Quartz, and more, and the player can gain the emeralds they need by trading the crops or smooth stone already availiable in the End—effectively making the End a closed-loop system that eventually needs nothing from the outside world.