How to Build a String Farm in Minecraft

String is used for bows, fishing rods, crossbows, leads, wool (4 string = 1 wool), scaffolding, candles, and looms. Spiders are the primary source of string, dropping 0 to 2 per kill. A dedicated string farm uses spider spawners or darkroom designs to produce string in bulk. This guide covers both methods.

Why build a string farm?

• Bows, crossbows, and fishing rods all consume string in crafting and repair.
• Leads (2 string + 1 slimeball) are essential for transporting animals.
• String converts to wool (4 string = 1 white wool) for emergency bed crafting.
• Scaffolding (6 bamboo + 1 string) is the best building aid in the game.
• Tripwire hooks and tripwires use string for redstone contraptions.

Materials list

Item	Quantity	Notes
Water buckets	4 to 8	Mob transport
Signs	8+	Water control
Building blocks	100+	Channels and structure
Hoppers	4+	Collection
Chests	2+	Storage
Slabs or trapdoors	varies	Kill chamber
Torches	varies	Construction lighting
Magma blocks (optional)	varies	Alternative kill method

Option 1: Spider spawner farm

Step 1: Find a spider spawner

Spider spawners are found in mineshafts (cave spider spawners) and occasionally in dungeons (regular spider spawners). Cave spider spawners are surrounded by cobwebs and are more common but harder to work with because cave spiders are poisonous and smaller.

Step 2: Clear the area

For cave spider spawners, clear all cobwebs around the spawner (use shears or a sword). Light the area with torches to prevent spawns during construction. Expand the room to 9x9 centered on the spawner with 2 blocks of headroom.

Step 3: Build water channels

Spiders are 2 blocks wide and 0.9 blocks tall. They can climb walls. To handle this, use water streams to push them and build channels that are 2+ blocks wide. Spiders cannot climb through water. The water channels push spiders toward a drop shaft or kill zone.

Step 4: Build the kill zone

Spiders can climb out of standard drop shafts. Solutions:

• Line the shaft walls with glass (spiders cannot climb glass).
• Use a water column inside the shaft (spiders cannot climb in water).
• Place magma blocks at the bottom (spiders die from magma damage, no XP but AFK-friendly).
• For XP, use a 1-block-wide slit at the bottom where you can hit spiders with a sword. The slit must be only half a block tall to prevent spiders from escaping.

Side view (spider spawner farm):

  [SPAWNER ROOM - water pushes right]
       |
  [GLASS-LINED DROP SHAFT]
       |
  [SPIDERS accumulate]
  [HALF-SLAB gap]
  [PLAYER position]
  [HOPPER] > [CHEST]

Option 2: Darkroom spider farm (no spawner)

Build a darkroom at least 8x8 and 1 block tall (spiders need only 1 block of vertical space). This height prevents zombies, skeletons, and creepers from spawning (they need 2 blocks). Only spiders and small mobs can spawn. Use water streams to push spiders to a kill zone.

Step 1: Build the 1-block-high spawning chamber

Create a large, dark chamber with exactly 1 block of air between the floor and ceiling. Make it at least 16x16 for decent spawn rates. Spiders spawn on the floor and immediately get pushed by water.

Step 2: Add water channels

Place water sources along one wall, flowing toward the opposite wall. At the opposite wall, build a funnel into a drop shaft lined with glass.

Step 3: Kill and collect

Same as the spawner design. Use glass-lined shafts, magma blocks, or manual sword kills.

Option 3: Cat gift farm

Tamed cats bring gifts to the player when sleeping (waking up from a bed). Gifts include string (about 16.1% chance per cat). With 20 tamed cats nearby, you average about 3 string per sleep cycle. This is very slow but completely passive and requires no combat or spawning mechanics.

Spider drop rates

Drop	Base rate	With Looting III
String	0 to 2 per kill	0 to 5 per kill
Spider eye	33% chance of 1	33% chance of 1 to 4
XP	5 per kill	5 per kill

Cave spider vs. regular spider

Property	Regular Spider	Cave Spider
Size	2 blocks wide, 0.9 tall	1 block wide, 0.5 tall
Health	16 HP (8 hearts)	12 HP (6 hearts)
Poison	No	Yes (Normal and Hard difficulty)
Drops	Same (string + spider eye)	Same (string + spider eye)
Spawner location	Dungeons (rare)	Mineshafts (common)

Common mistakes

• Spiders climbing out. Spiders climb any non-glass surface. Use glass walls in the drop shaft and kill chamber. Water columns also prevent climbing.
• Kill gap too large. Spiders are 0.9 blocks tall. A 1-block gap lets them crawl through. Use a half-slab gap (0.5 blocks) for the kill slit.
• Cave spider poison. On Normal and Hard difficulty, cave spiders inflict poison. Bring milk buckets or a shield. Poison does not kill you (leaves you at 1 HP), but it reduces you to dangerously low health in combination with attack damage.
• Not clearing cobwebs. Cave spider spawner areas are choked with cobwebs. Cobwebs slow you and prevent water from flowing. Clear every cobweb before building channels.
• Darkroom too tall. If the darkroom ceiling is 2 blocks high instead of 1, zombies, skeletons, and creepers spawn alongside spiders. Use exactly 1-block height for spider-only spawning.

Frequently asked questions

What is the best string farm design?

A cave spider spawner farm is the most efficient per-block design because spawners ignore the mob cap and produce mobs consistently. If you do not have a spawner, a 1-block-tall darkroom is the best darkroom alternative.

Can I turn string into wool?

Yes. 4 string = 1 white wool on a crafting table. This is useful when you need wool but do not have sheep nearby. The wool can be dyed any color after crafting.

How much string do I need for scaffolding?

6 bamboo + 1 string = 6 scaffolding. String is the limiting resource for mass scaffolding production. A spider farm producing 200 string per hour supports the creation of 1,200 scaffolding per hour.

Do spider eyes have any use?

Spider eyes are a brewing ingredient for potions of poison (spider eye + awkward potion) and fermented spider eyes (spider eye + sugar + brown mushroom). Fermented spider eyes are used in potions of weakness, harming, and invisibility. They are valuable for brewing setups.

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