Minecraft wiki entry for Combat, associated text: Spiders can be a nuisance if handled incorrectly. They are one of the monsters that are 1 block high, and as such, they will be able to sneak into the player's house if a hole is sufficiently large for them. However, spiders are also 2 blocks wide, so a 1×1 hole will not let them pass. Spiders have a special feature in which they can climb blocks. If players hear spider noises but can't see one, usually they are on top of their house. In the daytime, spiders will become neutral — they will only attack players if they attack them (but if they were hostile towards players during the night, they will still stay hostile). Also, even in their neutral state, if players try to sleep in a bed the usual "You can't sleep there are monsters nearby" message appears. However, they can ambush players in the daytime if players exit their house when one is on their roof, attacking their back as they walk away from their house. Spiders have a jump attack, and so it is best to swing a sword while walking backwards to avoid most damage. During the day, they can be killed by lava or flint and steel without becoming hostile to the player. In Survival, a spider becomes neutral towards the player if the light level around them is around 12. One can also kill spiders by pillar jumping, creating a ledge around the pillar, bombing the spiders with snowballs, and watching them climb and fall.