Memory Idioms 2Versión en línea Players will try to match the idiom with it's meaning. por Lunarn Smith Happens very rarely; uncommon Burn the midnight oil Tell a secret Ants in one’s pants It’s not hard. Good idea or invention Once in a blue moon Let the cat out of the bag Don’t start problems or cause trouble Hold your horses Cost an arm and a leg Let sleeping dogs lie It’s not rocket science Best thing since sliced bread Very expensive Wait and be patient Can’t stay calm (relax) because you’re nervous Work until late at night