Minecraft wiki entry for Allay, associated text: Allays have a luminous texture, allowing them to be seen clearly in the dark. They fly around aimlessly until given an item. It will appear to hold that item in its hand and will scan the area around the player for examples of that same item, where it will then return it to the player. A player will get the item back if an allay is interacted again while the player has an empty inventory slot.