A bird is known by its note, and a man by his talk. 听音识鸟，闻言识人。
Birds in their little nests agree. 同巢之鸟心儿齐。
Cats hide their claws. 知人知面不知心。 
Don't count your chickens before they're hatched. 不要过早乐观。
Love me, love my dog. 爱屋及乌。
Dog does not eat dog. 同类不相残。
The frog in the well knows nothing of the great ocean. 井底之蛙，不知大海。
The fox may grow grey, but never good. 狐狸毛色可变，但是本性难移。
Never offer to teach fish to swim. 不要班门弄斧。
A horse may stumble on four feet. 马有四条腿，亦有失蹄时。
A speck of mouse dung will spoil a whole pot of porridge. 一颗老鼠屎，坏了一锅粥。
One swallow does not make a summer. 一燕不成夏。
If you don't enter a tiger's den, you can't get his cubs. 不入虎穴，焉得虎子。
Who keeps company with wolves, will learn to howl. 和狼在一起，就会学狼叫。
He that makes himself a sheep shall be eaten by the wolf. 甘心做绵羊，必被豺狼吃。
You cannot run with the hare and hunt with the hounds. 人不应两面讨好。