Minecraft wiki entry for Experience, associated text: Experience orbs with negative values can be created using the /summon command, either using values below 0 or above 32767 due to 16-bit integer overflow. They have the smallest texture of experience orb. While collecting them does not affect the player's experience bar in any way, they can deduct durability from a tool enchanted with Mending, provided the tool is already damaged prior to collection of the orbs.[2]