Smell a rat 觉得可疑
I smelt a rat when he started being so helpful!
The rat race 激烈的竞争
Living in a big city is one big rat race
Play cat and mouse with sb. 欲擒故纵，（像毛抓耗子似地）欺负（折磨、虐待）某人
The policeman decided to play cat and mouse when he saw the woman steal the dress in the store.
A bull in a china shop 经常闯祸的人，笨手笨脚的人
He is like a bull in a china shop, always knocking things over.
Take the bull by the horns 不畏艰险
You can not just sit back in a situation like this. You should take the bull by the horns.
Like a red rag to a bull 使愤怒
Any staement against the government is like a red rag to a bull to that minister.
Till the cows come home 永远地，无限期地
If you are waiting for him to pay you, you will wait till the cows come home!
Paper tiger 貌似强大而实质虚弱的敌人，纸老虎
As long as we are not afraid of this kind of threat, the paper tiger’s true face will come out.
Hunt with the hounds and run with the hare 同时支持相对立的两派，脚踩两只船
Which team are you going to support? Make up your mind now. You can not hunt with the hounds and run with the hare.
Sow （the）dragon’s teeth 挑起纠纷或引起争端
Wherever he went, he sowed (the) dragon’s teeth by preaching racial segregation.
A snake in the grass潜伏的危险敌人，阴险而伪善的朋友
How could I ever trust that snake in the grass?
Hold your horses 忍耐，克制，别急躁
Don’t get so angry. Just hold your horses and find the appropriate solution.
Put the cart before the horse本末倒置
Surely you are putting the cart before the horses by buying all this furniture before you have got the house.
Flog a dead horse 徒劳，浪费精力
You will just be flogging a dead horse if you try to make her change her mind about it.
A wolf in sheep’s clothing 披着羊皮的狼
Mrs. Martin in trusted the lawyer until she realized that he was a wolf in sheep’s clothing.
Monkey about /around 胡闹
The boys werer monkeying about in the playground, and one of them got hurt.
Cock one’s snook to sb. 瞧不起别人
The artist cocked a snook at the critics by exhibiting an empty frame.
A dog in the manger 站着茅坑不拉屎的人
Don’t be such a dog in the manger. Lend your bicycle to him since you will not go out this afternoon.
Top dog 处于支配到位
Brazil can well be said to the top dog in the soccer circles of the world.
Buy a pig in a poke(未见实物而)乱买东西（吃了亏）
You will have to show me the car; I don’t intend to buy a pig in a poke.