The creature will fight with its pincers until it has been stunned; if this occurs, while the creature will be unable to attack, it will reflexively twist its abdomen forward and release a cloud of boiling, superheated acid in a 120-degree arc centered on the direction of the last successful attack. The cloud emerges as a liquid gas, causing skin burns that are very painful. cause 3-12 damage to all opponents to a distance of 3 combat hexes (15 feet). Characters suffering 8 or more damage from the cloud will be unable to wear armor for 1-4 days afterwards.
In addition, the sonic boom of the cloud's release is so intense that anyone within 6 hexes will be made deaf for 1-4 rounds (no saving throw); spellcasters will have their concentrations broken by this effect to a distance of 12 hexes.
Following its cloud attack, the bombadier beetle will seek to escape, moving continuously for 100-400 yards before stopping.
During chilly weather (30-39°F), the bombadier beetle is not active. Once this (or colder) weather becomes continuous, the beetle will bury itself in mulch or loam until the following spring.