The 7 Most Popular Animal Idioms in English, Selected and Explained by Speak Up

Descubre la selección -y explicación- de Speak Up de las 7 expresiones con animales en inglés (animal idioms) más usadas. Algunas han hecho su paso al español casi literalmente.

Actualizado a

7 Most Popular Animal Idioms
Imprimir

One idiom that many language learners seem to know is ‘It’s raining cats and dogs’, meaning that it is raining heavily. The only problem with this idiom is, while it is funny and conjures up a vivid image, it is rarely used by native speakers. As language learners, we have to be careful how we use idioms in our second language, if we over-use them it sounds strange and if we don’t use them at all, then we miss out on sounding fluent and comfortable with the language. Here we have put together 7 idioms with animals that are used frequently and that you may hear in a conversation with native speakers and non-native speakers of English.

The 7 Most Popular Animal Idioms in English Explained

1. To be a fly on the wall

Meaning: To secretly listen to or observe something without being noticed.

Origin: This idiom dates back to the early 20th century and paints the image of a tiny fly sitting unnoticed in a room, watching everything that happens. Imagine if you could turn yourself into a fly and go and listen to private conversations anywhere you want! We mostly use this idiom as I hypothetical wish starting ‘I would love to be….’

Example: "I’d love to be a fly on the wall when the managers are discussing the new staff cutbacks to hear what they really think!" ("¡Me encantaría ser una mosca en la pared cuando los directivos discutan los nuevos recortes de personal para escuchar lo que realmente piensan!").

2. To let the cat out of the bag

Meaning: To accidentally reveal a secret.

Origin: This phrase dates back to markets in the 1700s, when unscrupulous sellers would sometimes trick customers by selling them a cat in a sack instead of a piglet! When the cat was let out, the deception was revealed.

Example: "I let the cat out of the bag and told him about the surprise party too soon." ("Se me escapó el gato y le conté lo de la fiesta sorpresa demasiado pronto".

3. When the cows come home

Meaning: Something that is likely to take a very long time, or may never even happen at all.

Origin: This idiom originates from the fact that cows are known for moving slowly, often wandering for long distances before returning home. The phrase has been used for centuries to describe things that will take ages to happen, if they happen at all.

Example: “Ben said he would tidy his room, but we can expect that to happen when the cows come home.” ("Ben dijo que ordenaría su habitación, pero podemos esperar que eso ocurra cuando las vacas vuelvan a casa").

4. When pigs fly

Meaning: Something that will never happen.

Origin: Since pigs can’t fly, the idea is that it’s a humorous way to describe something impossible. The phrase has been in use since at least the 1600s and most languages have their own equivalent like ‘When there are two Thursdays in the week’ (Italy and Denmark) or ‘When donkeys fly’ (Italy) or ‘when frog’s grow hair’ (Spain) or ‘when a cactus grows on my hand’ (Poland) or my favourite ‘when chicken grow teeth’ (France)  .

Example: "He said he’d try ballet classes when pigs fly." ("Dijo que probaría las clases de ballet cuando los cerdos vuelen").

5. The elephant in the room

Meaning: A big, obvious problem that everyone is avoiding.

Origin: This idiom refers to a situation where there’s an obvious issue (like a giant elephant in a room) that no one wants to acknowledge. It was first recorded in the 20th century. We often use it when we are about to be brave and admit that there is a really important topic that everyone is avoiding talking about.

Example: "We can’t ignore the elephant in the room—our profits are decreasing." ("No podemos ignorar el elefante en la habitación: nuestros beneficios están disminuyendo").

6. To take the bull by the horns

Meaning: To confront a problem or challenge head-on.

Origin: This phrase likely comes from rodeo or bullfighting, where controlling a bull by its horns is the most direct way to assert control over the animal. It’s been used since the 1800s.

Example: "Instead of waiting for the issue to resolve itself, she decided to take the bull by the horns and deal with the problem immediately." ("En lugar de esperar a que el asunto se resolviera por sí solo, decidió coger el toro por los cuernos y abordar el problema de inmediato").

7. Hold your horses

Meaning: Wait, slow down, or be patient.

Origin: This phrase comes from horse riding, where the rider might need to pull on the reins to stop or slow down their horse. It has been in use since the 19th century.

Example: "Hold your horses! We haven’t finished setting up the equipment yet." ("¡Aguanta a tus caballos! Aún no hemos terminado de montar el equipo").

Do you want to know more popular idioms in English? Have a look at 15 frases hechas o “idioms” en inglés para el día a día (por niveles).

Animal idioms add fun and color to your English. Why not take the bull by the horns and start using an idiom now and again! The exercises below will help you to practise them.

Fill in the blanks with the correct animal idiom

1. I wish I could be a ________ during their meeting to see how it really went.

2. You need to ________ before we rush into making a decision.

3. My dad will clean the kitchen without being asked ________.

4. We can’t keep avoiding the ________—there’s a major error in the report.

5. Instead of worrying, she decided to ________ and solve the issue right away.

6. We are likely to be here until the _________, the trains are not going to run in this heavy snow.

7. It’s a surprise party so don’t mention anything to David, if you _________, you’ll spoil the surprise.

Answers:
1. fly on the wall
2. hold your horses
3. pigs fly
4. elephant in the room
5. take the bull by the horns
6. when the cows come home
7. let the cat out of the bag

More in Explore

5 consejos para no olvidar el inglés que aprendemos
iStock

Tips and resources

5 consejos para no olvidar el inglés que aprendemos

Para que la información se nos quede grabada de forma permanente, tenemos que repasarla constantemente. Aquí te doy algunos consejos sobre cómo incorporar ese repaso a tu día a día.

Natalie Gommon

TODAY’S TOP STORIES

Julian Barnes: Truth and Delusion
Free image

Classic Books

Julian Barnes: Truth and Delusion

En su obra, que incluye títulos como El loro de Flaubert, la novela ganadora del premio Booker El sentido de un final, o la más reciente La única historia, el autor inglés trata temas como la historia, la identidad y la memoria. Barnes es además una de las grandes figuras literarias que se lamentan del absurdo de la salida del Reino Unido de la UE.

Alex Phillips