The new security guard is a burglar----that’ll set the cat among the pigeons. 新来的警卫是个小偷----这下可要鸡犬不宁了。
8）rain cats and dogs 下倾盆大雨
You’d better stay in. It’s raining cats and dogs outside. 你最好呆在屋里。外面正下大雨。
9）When the cat is away, the mice will play.（谚语）山中无老虎，猴子成霸王。
10）bell the cat （为众人）主动冒险
He offered to bell the cat when the others refused to go. 别人都不想去的时候，他提出要去冒一下险。
11）wait for the cat to jump / see which way the cat jumps 待情况明朗后再作决定
We needn’t make a decision yet. We have to see which way the cat jumps. 我们现在还用不着做出决定。我们还要看一看形势。
12）（as） sick as a cat 直想呕吐
Sorry to say, I am sick as a cat. 对不起，我直想呕吐。
13）A cat in gloves catches no mice. （谚语）戴手套的猫抓不着耗子。（怕弄脏手的人什么事也做不成。）
14）A cat may look at the king. （谚语）猫也可以看国王。（小人物也该有权利。）
15）（as） weak as a cat 身体非常虚弱
He is often absent from school, because he is as weak as a cat. 他总是缺课，因为他身体太虚弱了。