Bell

"Ding dong, who's there? A RAID? GET INSIDE!!!"

- Adrian Östergård

Bells are transparent animated block entities that produce a bell sound when.

Obtaining
A bell does not have a crafting recipe and requires a pickaxe to be mined or it will drop nothing.

Natural generation
Bells can generate naturally in all village variants, usually near the center of the village in the meeting point.

Trading
Apprentice-level Armorer villagers have $1/3$ chance to sell a bell for 36 emeralds. Apprentice-level Toolsmith villagers sell bells for 36 emeralds. Journeyman-level Weaponsmith villagers sell bells for 36 emeralds.

Usage
When the side of a bell is, it will produce a sound as well as a "swaying" animation. Bells can be anchored to the side of blocks, ceilings, and floors. Also, if the player the bell while villagers are sleeping, all of the villagers will wake up.

When rung, villagers will run into their houses immediately as they do at sunset.

Additionally, the bell will also apply the Glowing effect to any raid mobs within 48 blocks (64 in 1.14.2), and produce a resonating sound if any such mobs are within range.

Block entity
A bell has a block entity associated with it that holds additional data about the block.

Trivia

 * On the Bedrock Edition, bells used to have unused data values with only side texture without bell which cannot be rung.
 * On the Bedrock Edition, bells can be powered by redstone and any projectile. The bell will deflect any projectile that doesn't disappear when hitting a surface (arrows or tridents).
 * Despite some villages generating with more than one bell, villagers only need one of them to meet and spawn iron golems. When 2 or more generate it is recommended to take one if the player plan to start their own village and/or iron farm, or place it in different place but still near claimed beds, so villager will split their crowd into two different cluster.