Spiders are neutral mobs that spawn naturally in the Overworld.
Spiders spawn naturally in the Overworld and sometimes in leaves as well. They also spawn inside Caves and Dungeons, from Monster Spawners, or from a Spider Spawn Egg. In Abandoned Mineshafts, Cave Spiders spawn instead of Spiders.
Spiders are neutral mobs, but will attack the player at night even if not provoked. During sunlight, they will not attack the player, unless provoked. The same happens with Cave Spiders.
Spiders attack by jumping on the player or above the player. They can also climb over all blocks, even fences and Cobblestone Walls making them dangerous.
Due to their low life, Spiders can be easily killed with a Wooden Sword with 4 hits. However, a Bow would work better when fighting groups of Spiders.