There is a well-known expression in English - "Time flies when you're having fun" - here the frog has changed the expression, as they are having (eating) flies, which for them is fun.
英文裡有句話，Time flies when you're having fun，「快樂的時光過得特別快」。青蛙改變了說法，「吃蒼蠅（flies）的時光特別快樂！」
網址：www.britishcouncil.hk/english
■漫畫&說明︰英國文化協會
逢星期五見報