Tantrum

From DwarfFortressWiki

Dwarves are fickle creatures, and when pressed to the breaking point of their happiness, they will tantrum. A tantruming dwarf may attack people and animals, destroy buildings, or throw things. The dwarf will receive happy thoughts from doing this. Those acts are generally considered a crime.

Dwarves will tantrum if they are at the "very unhappy" level of happiness or worse. If a dwarf has created a masterpiece-level item, they will also throw a tantrum if it rots, or is ever destroyed or stolen. Masterpiece engravings can be destroyed by miners digging out walls or floors.

However, dwarves will not tantrum if a masterwork item is sold to foreigners, or if a masterpiece building is dismantled.