Spider

Spider is a neutral arthropod that spawns in the dark throughout the Overworld and turns hostile only in low light.

In Java Edition it needs a light level of 0 and a 3×1×3 space, and it appears in every biome except mushroom fields and the deep dark; in Bedrock Edition it also avoids rivers, frozen rivers and snowy plains, never spawns in groups, and is replaced by cave spiders in sulfur caves. Monster rooms in dungeons have a 25% chance of holding a Spider spawner, more sit in the cobweb-filled secret rooms of woodland mansions, and 1% of naturally spawned Spiders arrive as a spider jockey, with a skeleton riding on top.

Spiders drop 0–2 string, rising to 0–5 with Looting III. When killed by a player or a tamed wolf they also drop 0–1 spider eye, rising to 0–4 with Looting III. The same kill is also worth 5 experience.

Spiders cannot be bred and have no baby form, so they come only from natural spawning in the dark and from spawners — which is why a spawner farm is the usual way to gather string in bulk. A name tag will keep an individual Spider from despawning.

Spider hostility depends on light, not on the time of day. It attacks on sight when the light level immediately around it is 11 or lower, and stays neutral above that unless it is attacked first. Unlike zombies and skeletons it does not burn in sunlight, so a Spider that spawned overnight survives into the day and turns hostile again as soon as it reaches shade. A hostile Spider can see a target up to 16 blocks away.

Spiders climb any solid vertical surface, though they cannot hang from the underside of a block. Their hitbox is 1.4 blocks wide and only 0.9 blocks tall, so they squeeze through 1-block-high gaps that stop most mobs but cannot fit into a 1-block-wide corridor. They have 16 health, deal 2 damage on Easy and Normal and 3 on Hard, and take extra damage from the Bane of Arthropods enchantment.