Animal idioms

a sly fox / to be as sly as a fox

Someone who is very experienced and has acquired a lot of guile.

to let sleeping dogs lie

To leave well alone and refrain from starting trouble.

You must have known that mentioning his ex-wife would upset him. You should have let sleeping dogs lie.

as stubborn as a mule

someone who is unwilling to listen to reason or change his mind.

a dark horse

A person of unknown abilities or a person who has kept his abilities to himself and may surprise everybody. This is a racing metaphor which says that an unknown horse which could win the race unexpectedly.

Who would have thought George would win the competition? He's a real dark horse.

no room to swing a cat

A very small, cramped place. The original phrase was probably 'not room to swing a cat-o'nine-tails', and dates from the time when sailors were whipped (flogged) on ships. The floggings took place on the deck because the cabins were too small.

This room's not big enought to swing a cat in.

to put/set the cat among the pigeons

To provoke a quarrel.
You shouldn't have criticized the boss in your speech; now you've really put the cat among the pigeons.

a dog's-body

One who does the routine or mechanical work, especially that which no one else wants to do.
When I worked in the factory I was the dog's-body; I was given all the worst jobs.

as weak as a kitten

Feeble, very weak, having no strength.

After her operation she felt as weak as a kitten.