Spider

Spiders are a mob 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 to this since they drop string, a very useful ingredient for crafting a bow. Spiders were not added until alpha 0.3.3. Spiders are able to climb without Ladders.

Offense
They attack slow, and can be knocked out easily. Spiders take half a heart of damage for each hit with a bare hand. Spiders do about one to three hearts of damage per encounter.Spiders have an ability to climb any blocks including fences.They attack you by pouncing you plus cave Spiders poison you on hard so bring milk to abandoned mines and drink it to remove Poison.

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 weakest hostile mob on the game), even a wooden sword can take it down in a mere 4 hits. 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. Use a 4 by 4 lava trap to trap them. Try to hide in your base sniping!

Trivia

 * Spider's eyes do not glow unlike the PC/Mac version.
 * Spiders are the only mob in the game to be neutral and 2 blocks wide.
 * Spiders, like Zombies and creepers, have no weapons to attack with.
 * Spiders don't burn in daylight just like Creepers.
 * Spiders are almost as weak as silverfish.