Spider

Spiders are common neutral mobs which have the ability to climb walls.

Spawning
Spiders spawn in 3×3×2 space on opaque blocks (they need only 1 solid block beneath) at a light level of 7 or less, in groups of 4. The top blocks can be transparent, but not solid.

A Spider spawn in leaves provided that there are 3×3×2 spaces around, so forested biomes have a greater amount of spiders; they do not spawn in groups.



Monster spawners
Spider spawners are found in 25% of dungeons. They also spawn from spawners in hidden rooms surrounded by cobwebs in woodland mansions.

Status effects
On hard difficulty, spiders occasionally spawn with status effects. For each pack spawn, there is a (10&times;clamped regional difficulty)% chance of the game applying a status effect. This does not apply to cave spiders. If it decides to do so, then it selects the effect. The spider can spawn with following effects: The effect is then applied to all entities within the pack with an endless length. If the Invisibility status effect is applied to a spider, its eyes remain visible.
 * (40% chance)
 * (20% chance)
 * (20% chance)
 * (20% chance)

Drops

 * 0–2 . The maximum is increased by 1 per level of Looting, for 0-5 string with Looting III.
 * 5 when killed by a player or tamed wolf.
 * A $1/3$ chance of dropping a spider eye when killed by a player or tamed wolf. The maximum amount of spider eyes is increased by 1 per level of Looting. The chance of a spider not dropping any spider eyes can be found using the formula . For example, Looting III gives a $1/3$ chance of not dropping any spider eyes. All other amounts have an equal chance of occurring.

Behavior
Spiders are hostile to players and iron golems as long as the light level immediately around them is 11 or less; otherwise, they do not attack unless attacked. Hostile spiders see up to 16 blocks, continuing to chase even when exposed to well-lit locations. If a spider sustains damage from a source other than a direct attack, such as falling, its hostility is reset.

Spiders can climb up over solid blocks but not overhangs or on ceilings. If a spider cannot find an ideal path to the player, when she/he goes behind or on top of a wall, it approaches as close as it can to the player's position from the outside or below as it can see through blocks, at that time proceed by climbing the wall vertically until it gets to the top, even if it loses its aggression toward her/him. When a spider loses its aggression, it continues moving forward blindly for 2 seconds; this behavior causes the spider to climb up any walls in its path.

Spiders cannot climb magma blocks.

If a spider tries to go through the world border, it starts climbing the world border instead.

If shot with arrows whereas outside of the detection range, spiders turn and run in the direction from which the arrow was fired. If the player moves away, the spider continues following the same path unless the player enters detection range, in which case the spider changes direction and attacks.

Even though spiders do not inflict the Poison status effect, they are immune to it. Therewithal, they are immune to the slowing applied to most mobs when walking through cobwebs.

An agressive spider pouces at close range. Whether it is swimming in 1-block-deep water, it pounces upon touching the submerged floor.

Spiders flip onto their backs when they die, unlike all other mobs, which land on their sides.

They were the first arthropod to be added to the game, so the Bane of Arthropods enchantment inflict Slowness IV and more damage to spiders. Only dealing damage when their Y-axis position is changed, a spider being one block below is an efficient strategy whereas the user is fighting.

Spider jockeys
There is a 1% chance for a spider to spawn with a skeleton riding it, forming a spider jockey. In the Nether, a spider spawned there with a spawn egg, commands or spawners, has a 0.8% to spawn a wither skeleton on its back and form a wither jockey instead. In some of snowy biomes, a spider has a 0.8% to spawn a stray on its back and form a stray jockey instead. A spider jockey can also be spawned by the command.



Data values
Spiders have entity data associated with them that contain various properties of the mob.