Minecraft wiki entry for Hopper, associated text: A hopper has an "output" tube at its bottom that can face down or sideways and provides a visual indication of which block the hopper is set up to drop its items into, if that block has an inventory. To place a hopper, use the Place Block control while aiming at the surface to which its output should face (Hoppers do not orient themselves automatically). To place a hopper directly on the face of an already interactable block, the player can sneak while placing the hopper. Attempting to place a hopper aimed on the bottom face of a block instead faces downward. With some blocks, such as the furnace and brewing stand, the hopper has multiple uses. A hopper does not change direction after placement, and it is not attached to the container it faces; the container can be removed or replaced, and the hopper remains unchanged.