Minecraft wiki entry for NPC, associated text: NPCs have no AI. They can neither move nor be pushed by other entities. They also cannot take damage nor be affected by potions. Nevertheless, the NPCs can still turn their body and stare at the nearest player if close enough. The NPCs can be pushed by sticky pistons from below or sides with a slime block attached and they can slide on ice when pushed. NPCs can also block minecarts from passing. Minecarts cannot go through NPCs.