Minecraft wiki entry for Egg_farming, associated text: If you have glowstone and nether quartz, you can optionally add a couple of top slabs on level one, next to the hoppers. Atop these you'll want a comparator facing out from the main chest, and next to it something to provide a comparison signal of 8. This corresponds to 13 stacks in the chest, which is enough for a full run. A cake with three slices eaten will do fine. You can then run a redstone trail from the comparator to a redstone lamp. Embedding the lamp in the ground near the entrance can let you reach it with 8 or less dust; any further, and you'll need a repeater in there too. This is not shown in the schematic, because without it this build does not need Nether materials.