Anti Spider Walls | Keep Spiders From Climbing!
Spiders cannot climb: Blocks which do not impede the player, such as grass, sugar cane, fire or flowers. Water or lava, but will behave as other mobs (swim/drown, burn).
Spiders cannot climb: Blocks which do not impede the player, such as grass, sugar cane, fire or flowers. Water or lava, but will behave as other mobs (swim/drown, burn).