Pigeonholes are craftable blocks that house pigeons, which fill their homes with waste when they rest inside. Dirty pigeonholes can be cleaned with a shovel, dropping a bone meal.
Pigeonholes are similar to beehives: they also keep pigeons inside when broken with Silk Touch, comparator reads the waste level the same as honey level, etc.
Obtaining
Pigeonhole can be crafted in a crafting table from wooden planks and a hay bale.
The block also generates as part of a dovecote and collapsed mail hub structures.
Usage
Pigeon housing
Pigeonholes can house up to 3 pigeons at a time. They can enter through any unobstructed side, top, or bottom, but can exit only from the front, and only if it is unobstructed by a block that has collision.
Pigeons try to enter a pigeonhole at night, during rain, or when they are tired after mail delivery. They first look for one that they remember as home (last rest), but if there is no pigeonhole there, or it already contains 3 pigeons when they arrive, they search the nearby area for another one.
Igniting or smoking (using campfire) a pigeonhole forces any pigeons inside to escape.
Waste
Each time pigeon exits a pigeonhole, it has a 20% chance (or 100% when tired) to increase waste level of a block.
Once it has the maximum waste level of 5, block changes its appearance. Shovel can then be used to clean the pigeonhole, resetting its waste level back to 0 and dropping a bone meal. Additionally, cleaning has a 1% chance to drop a diamond, granting a hidden advancement.
Automation
Pigeonhole can be cleaned by powering a dispenser containing a shovel. The dispenser must be directly facing the block.
Redstone signal
Pigeonholes have a redstone comparator output with a strength equal to the waste level in the block, with a maximum signal strength of 5 once the block is completely full and ready for cleaning.