Animal Words and Phrases in English: Idioms, Metaphors, and More

Count the animals in one ordinary conversation and you start noticing a pattern: the boss is a shark, the neighbor is a night owl, the plan is a dog's breakfast, and somebody, somewhere, is in the doghouse. English leans on animals constantly — for praise, for insult, for warning, for description — and the habit runs so deep that most speakers never pause to register it. This article pulls those expressions into the open, grouping them by creature, and explains where the vivid ones came from. Consider it a field guide to the menagerie hiding inside a shelf of English idioms.

Why Animals Are Everywhere in English

English took shape in a farming culture. The settlers who carried Old English across the North Sea lived within arm's reach of livestock, and their vocabulary showed it: "horse," "cow," "sheep," "pig," "dog," "cat," "hen," "goat," "deer," and "fish" are all native Anglo-Saxon words, in use before the Norman Conquest. After 1066, a second layer arrived with the French-speaking aristocracy, and that layer mostly covered what landed on the table — beef, pork, mutton, veal, venison — producing the famous farmer-versus-diner split the language still carries. For more on that layering, see our piece on French borrowings.

On top of the naming comes the symbolism. English speakers have spent a thousand years reaching for a specific animal when they need a shortcut to a human trait: lions for bravery, foxes for cleverness, mules for obstinacy, dogs for loyalty, chickens for fear, bees for industry, swans for grace. The pairings are not always fair to the animal, but they are compact, instantly readable, and stubbornly useful.

Sayings Involving Cats

• "Let the cat out of the bag" — To spill a secret. The often-quoted origin involves a market swindle: a merchant pretends to sell a piglet but substitutes a cat, and the con collapses the moment the bag is opened.
• "Curiosity killed the cat" — A warning that nosing around too much gets you in trouble. (The original full proverb ends with "but satisfaction brought it back.")
• "Cat got your tongue?" — A prompt aimed at someone gone suspiciously quiet.
• "Raining cats and dogs" — Pouring down. Theories range from the poor drainage of early London streets to a misreading of older Greek expressions.
• "The cat's pajamas" / "The cat's meow" — Jazz Age slang for something first-rate.
• "Playing cat and mouse" — Teasing a helpless opponent with alternating attention and disinterest.
• "Like a cat on a hot tin roof" — Jumpy; unable to settle. Tennessee Williams built a play around the image.
• "No room to swing a cat" — Extremely cramped. The "cat" here is widely argued to be the cat-o'-nine-tails, a naval whip that needed clearance.
• "Catnap" — A brief, shallow sleep, named for the way cats nod off in short cycles.
• "Fat cat" — A rich, entrenched, self-satisfied figure, often used of donors and executives.

Sayings Involving Dogs

• "Every dog has its day" — Even the most overlooked person eventually gets a turn.
• "Let sleeping dogs lie" — Do not disturb a quiet situation. Reviving a grievance rarely ends well.
• "Dog-eat-dog" — Savage competition, often used of industries or marketplaces.
• "Barking up the wrong tree" — Pursuing an idea that cannot pay off — a hunting dog that has cornered an empty tree while the quarry has moved.
• "A dog's life" — A bleak existence. It dates from an era when dogs were working animals rather than sofa companions.
• "In the doghouse" — Out of favor, particularly with a spouse.
• "Dogged" — Persistent past the point of sense, in a way that grudgingly earns respect.
• "Underdog" — The expected loser. It traces back to dogfighting, where the dog pinned beneath its opponent was the "under" dog.
• "Puppy love" — The intense, short-lived crush characteristic of adolescence.
• "You can't teach an old dog new tricks" — Old habits resist rework.
• "Hair of the dog" — An early-morning drink intended to dull a hangover, from the folk belief that a dog bite could be treated with hair from the offending dog.

Sayings Involving Horses

• "Straight from the horse's mouth" — Firsthand information. A horse trader could tell a horse's age by checking its teeth, so "the mouth" was the unmediated source of truth.
• "Hold your horses" — Slow down; wait.
• "Don't look a gift horse in the mouth" — Do not audit the value of something given freely.
• "Dark horse" — An unknown competitor who wins. It comes from the racing shorthand for a horse whose form had been kept secret.
• "Get off your high horse" — Drop the superior attitude. Aristocrats once rode deliberately tall mounts in processions.
• "Horsing around" — Messing about, usually harmlessly but sometimes expensively.
• "Flogging a dead horse" (or "beating a dead horse") — Persisting at something that will not move.
• "Put the cart before the horse" — Order the steps wrongly.
• "Horsepower" — James Watt coined the unit so steam engines could be advertised in terms buyers already understood.
• "Nightmare" — The "mare" here is Old English mara, a malevolent spirit thought to sit on a sleeper's chest. It has nothing to do with a female horse, though the phonetic coincidence is strong.

Sayings Involving Birds

• "A little bird told me" — A playful refusal to name a source.
• "Kill two birds with one stone" — Achieve two results from one effort.
• "Birds of a feather flock together" — Similar people gravitate toward each other.
• "Eagle-eyed" — Extremely sharp sighted, literal or metaphorical.
• "Swan song" — A farewell performance. Ancient writers claimed mute swans sang one perfect song as they died.
• "Crow's feet" — The fine lines that fan out from the corner of the eye.
• "Eat crow" — To publicly admit you were wrong.
• "Parrot" (as a verb) — To repeat words without grasping them.
• "Pecking order" — Social ranking, a term lifted straight from poultry biology.
• "Hen-pecked" — Dominated by a partner, used almost exclusively of husbands.
• "Nest egg" — A stash of savings. The name comes from the old trick of leaving one egg in the nest so the hen will keep laying.

Talk from the Water: Fish and Sea Life

• "A fish out of water" — Someone visibly stranded in a strange environment.
• "Red herring" — A misleading clue. Heavily smoked herring, dragged across a trail, can derail hunting dogs; detective fiction adopted the metaphor wholesale.
• "Plenty more fish in the sea" — Offered, usually unhelpfully, after a breakup.
• "Drink like a fish" — Consume alcohol heavily, despite the biological fact that fish do not actually drink water through their mouths.
• "Clam up" — Stop talking, the way a clam shuts at a touch.
• "Shark" — Applied to a predatory operator — loan shark, pool shark, card shark.
• "A whale of a time" — A spectacularly good one.
• "Crabby" — Short-tempered. Anyone who has wrangled a live crab understands the adjective immediately.

Expressions Borrowed from Wild Beasts

• "The lion's share" — The biggest piece. The phrase comes from Aesop, whose lion keeps the whole kill on various flimsy pretexts.
• "Crocodile tears" — Fake grief. Medieval bestiaries claimed crocodiles wept while eating, which modern biologists have mostly debunked.
• "Wolf in sheep's clothing" — A threat in a friendly disguise, originally a biblical warning against false prophets.
• "Elephant in the room" — The large, unavoidable problem everyone is pretending not to notice.
• "Monkey business" — Mischief with a whiff of dishonesty.
• "Foxy" — Cunning, or (in modern slang) attractive.
• "Bull market" / "Bear market" — Finance jargon grounded in animal behavior: bulls horn upward, bears swipe downward.
• "Scapegoat" — A blame-taker. The Levitical ritual loaded the community's sins onto a goat and drove it into the desert.
• "Rat race" — The grinding routine of modern salaried life.
• "Stubborn as a mule" — Immovable; a mule will sit down on a trail and simply wait you out.

Sayings Taken from Bugs

• "Busy as a bee" — Productive to the point of blur.
• "Butterflies in your stomach" — The flutter of pre-event nerves.
• "The bee's knees" — Top-shelf; excellent. Another piece of 1920s nonsense slang that somehow stuck.
• "A fly in the ointment" — A small thing wrecking a bigger one, borrowed from Ecclesiastes 10:1.
• "Ants in your pants" — Agitated to the point of squirming.
• "To bug" — To annoy. Also, since World War II, to install a hidden microphone.
• "Bitten by the bug" — Struck by sudden enthusiasm — travel bug, chess bug, gardening bug.
• "Snug as a bug in a rug" — As comfortable as it is possible to be.

Animal Names Doing Verb Duty

English loves turning nouns into verbs, and animal names end up doing a lot of the work:

• To badger — To pester without letup.
• To hound — To pursue like a tracking dog.
• To parrot — To repeat without understanding.
• To ape — To mimic.
• To weasel — To slither out of a commitment.
• To duck — To dip below something — a punch, a question, a responsibility.
• To hawk — To push a product on strangers in public.
• To ferret — To dig out information that didn't want to be found.
• To snake — To move in curves, as a river or a queue does.
• To buffalo — To intimidate by sheer bulk of presence, chiefly American.

Adjectives That Start as Animals

A separate family of animal-based words comes straight from Latin as adjectives, generally formal-register:

• Canine — dog-related, from canis.
• Feline — cat-like, from felis.
• Equine — horse-like, from equus.
• Bovine — cattle-like, from bos.
• Porcine — pig-like, from porcus.
• Vulpine — fox-like, from vulpes.
• Aquiline — eagle-like, especially of a nose, from aquila.
• Serpentine — winding, snake-like, from serpens.
• Leonine — lion-like, from leo.
• Lupine — wolf-like, from lupus.

Closing Thoughts

The animal layer of English is a kind of zoological shorthand for human life. Cats stand in for slinky independence, dogs for loyalty and occasional disgrace, horses for effort and pedigree, birds for gossip and freedom, fish for awkwardness, wolves for menace, bees for productivity. None of those mappings is scientifically precise, and some are frankly unfair to the animals involved, but together they form a compact vocabulary for talking about people without quite pointing at them. Keep an ear out — once you start tracking the creatures in everyday speech, you will spot one almost every hour. For a companion tour, see our guides to vocabulary, or dig into where these pictures of the world came from via our etymology overview.