Idioms based on animals and animal behaviour. Select an idiom for more details. Also try Animal Idioms Quiz.

(it's) raining cats and dogs

You can say "it's raining cats and dogs" if it's raining very hard.

(like) water off a duck's back

You can say an insult or criticism is like water off a duck's back if it doesn't upset you.

a night owl

You're a night owl if you like to stay up and do things late at night.

a queer fish

If someone's a queer fish, they are a bit strange and can sometimes behave in an unusual way.

a whale of a time

If you have a whale of a time, you have a great time and really enjoy yourself.

a wolf in sheep's clothing

A wolf in sheep's clothing is someone who seems to be a good person but is really a bad person.

can of worms INFORMAL

If you say a situation or an issue is a can of worms, you think that getting involved in it could lead to problems.

chickens come home to roost

If chickens are coming home to roost, someone is suffering the unpleasant consequences of their bad actions in the past.

drink like a fish INFORMAL

If someone drinks like a fish, they drink a lot of alcohol.

eyes like a hawk

If someone has eyes like a hawk, they have very good eyesight and they notice everything.

kill two birds with one stone

If you kill two birds with one stone, you achieve two things with the one action.

let the cat out of the bag

If you let the cat out of the bag, you let someone know a secret.

like a fish out of water

You feel like a fish out of water if you're surrounded by people who are different to you, and it's making you feel a little uncomfortable.

quiet as a mouse

If you're as quiet as a mouse, you're very quiet.

sick as a dog

If you're as sick as a dog, you're very sick.

take the bull by the horns

If you take the bull by the horns, you deal with a problem or a challenge in a direct and fearless way.

talk turkey

If you talk turkey, you discuss something seriously, usually to do with business or money.

the lion's share

You can say something is the lion's share if it's the biggest share or portion of something.

the rat race

The rat race is the highly competitive and stressful world of work and business.

zebra crossing British English

A zebra crossing is a pedestrian crossing that is marked on the road with painted black and white stripes.
Also try Animal Idioms Quiz.

Contributor: Matt Errey