a flea thus questioned an ox: "what ails you, that being so huge and strong, you submit to the wrongs you receive from men and slave for them day by day, while i, being so small a creature, mercilessly feed on their flesh and drink their blood without stint?" the ox replied: "i do not wish to be ungrateful, for i am loved and well cared for by men, and they often pat my head and shoulders.""woe''s me!" said the flea; "this very patting which you like, whenever it happens to me, brings with it my inevitable destruction."

一天，跳蚤问公牛:“你身体这么高大、强壮，为什么还要没日没夜地为人们劳动呢？我虽然个子不高，也没有力量，但是我却可以舒舒服服地靠吮吸人的血生活。【漫客文学】”公牛回答说:“我要报答人类对我的恩情才为他们工作的。他们精心地照顾我，还会亲切地抚摸我的肩膀和额头。”“哎呀！”跳蚤忍不住地大叫起来:“如果人们也那样抚摸我，我是会送掉小命的。”

对一个人是奖赏，对另一个人可能就会是灾难。