Minecraft wiki entry for Thunderstorm_survival, associated text: Witches are always hostile, and use potions offensively and defensively. Witches are deadly if approached by a player without nearby shelter or battle equipment, so avoiding them is beneficial when caught in the open. They may drop valuable loot, such as glass bottles and glowstone and health potions, but witches are rare outside of witch huts, so it is more beneficial to build a witch farm than to try to use thunderstorms to kill them.