The phrase "the unbelievable propensity to rioting that engaged the rest of the household" is an example of a literary device called hyperbole. Hyperbole is a figurative language technique that involves exaggeration or overstatement for emphasis or dramatic effect. In this case, the author is using hyperbole to emphasize the excessive and unruly behavior of the household, suggesting that their propensity for rioting is unbelievable or highly exaggerated.
