Spider

Spiders are neutral mobs that are two blocks wide and one block tall. They are hostile at night and neutral in the daytime unless attacked first by the player. If you want to make a Bow, they are vital since they are the only mobs that drop String. String is required to make a bow. Spiders are able to climb without ladders. There are currently no cave or jockey variants of the spider. In update 0.9.0 they will spawn by leaves.

Offense
They attack slowly and by jumping at you, and can be knocked out easily. Spiders take half a heart of damage for each hit with a bare hand (like with every mob). Spiders do about one to three hearts of damage per encounter. Spiders have an ability to climb any blocks including fences. Since 0.8.0 they have the ability to move much faster due to the new Mob AI system.

Defense
A Bow works best, as with most hostile mobs, but a Sword works too. Since a Spider only has 16 health points (making them the 2cd weakest hostile mob on the game, after Silverfish), even a wooden sword can take it down in a mere 4 hits, while an iron or diamond one can take them out in two. The bow, depending on the charge, can take it out in 2-4 hits. Even with bare hands it's only sixteen hits compared to a twenty hits to a Zombie or some Skeletons. Also, build slabs around your house to make sure that they cannot climb to the roof. You can also use a 4 by 4 lava trap to trap them.

Trivia

 * Spiders used to be the only mobs in the game to be neutral (only during day). However, ever since the Enderman and the Wolf were added in update 0.9.0, it does not hold this trait anymore.
 * Spiders, like Zombies and Creepers, have no weapons to attack with.
 * Spiders don't burn in daylight just like Creepers.
 * Spiders are one of the mobs that has to jump at the player to attack and that makes it sometimes hard to avoid if the player is running from the spider.
 * Spider farms are difficult to make since they can climb fences and fit in small spaces.
 * Spiders were not added until alpha 0.3.3.

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