撼树蚍蜉

词典解释

[an ant trying to shake a tree-ridiculously overrating oneself] 蚍蜉:一种大蚂蚁。蚍蜉想摇动大树。比喻不自量力者

成语解释

撼：摇动。蚍蜉：大蚂蚁。想把大树摇动的大蚂蚁。比喻自不量力者。