The Sculk Family

The "sculk family" is a family of blocks that generate exclusively in the deep dark biome. There are five different types of sculk blocks: sculk, sculk vein, sculk catalysts, sculk sensors, and sculk shriekers. All variants of sculk can only be obtained with a tool enchanted with Silk Touch. Any tool will work, but a hoe is the most efficient.

Sculk

Sculk is the most common member of the sculk family. It will generate covering deep dark biomes, and will also sometimes generate in ancient city chests. If they are mined without Silk Touch, they will drop one experience.

Sculk Vein

Sculk vein generates alongside sculk, and will drop nothing if mined without Silk Touch.

Sculk Sensor

Sculk sensors generate in small quantities in deep dark biomes, and are much more common in ancient cities. They can detect vibrations caused by the player, mobs, blocks being placed or broken, and a variety of other sources, up to eight blocks away. However, they will not detect any sounds made by other sculk sensors, sculk shriekers, or the warden. They also will not be able to hear wool or carpet being placed or broken. 

It is possible to avoid being detected by sculk sensors. If the player is sneaking or walking on wool or carpet, sculk sensors cannot detect them. Sculk sensors also cannot detect vibrations through wool, although they can still detect vibrations through other blocks.

Sculk sensors emit a light level of 1, and will drop 5 experience if mined without Silk Touch.

Sculk Shrieker

Sculk shriekers generate in small quantities in deep dark biomes, and are much more common in ancient cities. They function as the warden's alarm system, alongside sculk sensors. Sculk shriekers can be activated when a player walks on them, even if the player is sneaking, but they will typically be activated when a player activates a nearby sculk sensor.

Whenever a player activates a naturally generated sculk shrieker, they will be given 12 seconds of the Darkness status effect, which temporarily darkens the player's surroundings. One point will also be added to a "warning" scale. Once the scale reaches a level of four, the warden will be summoned. If the player does not activate another shrieker in the space of ten minutes, one point will be removed from the scale. Summoning a warden does not reset the scale to zero, meaning that more wardens can potentially be summoned.

Any sculk shriekers placed by the player or generated by a sculk catalyst do not count as naturally generated, and thus will not give the player the Darkness effect or summon the warden.

Sculk shriekers will drop 5 experience if mined without Silk Touch.

Sculk Catalyst

Sculk catalysts will generate dotted around deep dark biomes, and will sometimes generate in ancient city chests. They have the unique ability of converting nearby blocks into sculk when a mob that drops experience dies within eight blocks of it. When this happens, the sculk catalyst will convert one block into sculk for every experience point the dead mob drops (even if the mob was not killed by a player). This will also happen if a player that has collected experience dies near it.

The sculk blocks generated will have an edge of sculk vein generated around them, and there is also a small chance of it using ten experience points from the mob or player killed to create a sculk sensor or sculk shrieker. The chances of a sculk sensor generating are 9%, and the chances of a sculk shrieker generating are 1%.

Sculk catalysts will drop 5 experience if mined without Silk Touch.