What Is the Plural of Mouse?

The plural of mouse is mice. This is an irregular plural, meaning it does not follow the standard rule of adding -s or -es to the end of the word. Instead, the vowel sound changes from ou to i, a pattern seen in a small group of Old English nouns. Whether you are talking about the small rodent or a computer device, the correct plural form is mice.

Quick Answer

If you need a fast, direct answer: the plural of mouse is mice. Use mice for both animals and computer peripherals. Avoid mouses in standard English, though you may hear it in very informal or technical contexts. Stick with mice for clear, correct writing.

Why Is It Mice and Not Mouses?

The word mouse comes from Old English mūs. In Old English, some nouns formed their plurals by changing the vowel sound rather than adding a suffix. This is called umlaut or i-mutation. Other examples include foot becoming feet, tooth becoming teeth, and goose becoming geese. The plural mice has been standard for over a thousand years.

When computer mice were invented in the 1960s, the plural form naturally followed the same pattern. Although some early tech documents used mouses, mice quickly became the accepted term in both general and technical English.

Comparison Table: Mouse vs. Mice

Natural Examples

Here are examples of mouse and mice used in everyday situations. Notice how the context changes the meaning.

Rodent Examples

• Singular: A small mouse ran across the kitchen floor last night.
• Plural: We found mice living in the attic, so we called an exterminator.
• Plural: The barn cat caught three mice this week.

Computer Device Examples

• Singular: I need to replace my wireless mouse because the battery is dead.
• Plural: The IT department ordered twenty new mice for the office computers.
• Plural: Some gamers prefer wired mice for faster response times.

Formal vs. Informal Context

• Formal email: “Please ensure that all wireless mice are charged before the training session.”
• Informal conversation: “I think my mouse is broken. Can I borrow yours?”
• Technical documentation: “The system supports up to eight mice connected simultaneously.”

Common Mistakes

Even native speakers sometimes make errors with this word. Here are the most frequent mistakes and how to avoid them.

Mistake 1: Using Mouses as the Standard Plural

Some people write mouses because they think it follows the regular plural rule. While mouses appears occasionally in very informal speech or in early computer manuals, it is not considered correct in standard English. Always use mice.

Incorrect: The lab has ten mouses for the experiment.
Correct: The lab has ten mice for the experiment.

Mistake 2: Confusing Mouse with Moose

Some learners mix up mouse and moose. The plural of moose is moose (not meese). These are completely different animals, and their plural forms follow different rules.

Incorrect: We saw two meese in the forest.
Correct: We saw two moose in the forest.

Mistake 3: Using Mice for a Single Animal or Device

Remember that mice is always plural. Do not use it when referring to one mouse.

Incorrect: I saw a mice in the garden.
Correct: I saw a mouse in the garden.

Better Alternatives and When to Use Them

In most situations, mice is the best and only choice. However, there are a few rare cases where you might consider alternatives.

When to Use Mice

• In all standard writing: emails, reports, essays, articles, and books.
• In everyday conversation about rodents or computer devices.
• In formal and informal contexts alike.

When Mouses Might Appear (But Is Still Not Recommended)

• In very early technical documentation from the 1960s–1980s.
• In some niche gaming communities when referring to multiple types of computer mice (e.g., “gaming mouses”). Even here, mice is more common.
• In informal speech by people who are not aware of the standard plural.

Our advice: Stick with mice in all situations. It is universally understood and grammatically correct.

Mini Practice: Test Your Knowledge

Try these four questions to check your understanding. Answers are below.

Question 1

Which sentence is correct?

A. The pet store sold three mouses yesterday.
B. The pet store sold three mice yesterday.

Question 2

Fill in the blank: “I need to buy a new wireless _____ for my laptop.”

A. mice
B. mouse

Question 3

True or false: The plural of mouse is the same for both the animal and the computer device.

Question 4

Which word is an example of the same plural pattern as mouse → mice?

A. cat → cats
B. foot → feet
C. box → boxes

Answers

Answer 1: B. The pet store sold three mice yesterday.
Answer 2: B. mouse (singular)
Answer 3: True. Both use mice as the plural.
Answer 4: B. foot → feet (both use a vowel change to form the plural)

Frequently Asked Questions

1. Is mouses ever correct?

In standard English, mouses is not considered correct. You may encounter it in very old technical documents or in extremely informal speech, but mice is the proper plural form in all contexts.

2. Do I use mice for computer devices too?

Yes. The plural of a computer mouse is mice. This is the standard term in technology, business, and everyday language. For example, “The office has fifty mice for employees to use.”

3. Why does mouse change to mice and not mouses?

Because mouse is an irregular noun from Old English. It belongs to a small group of words that form their plurals by changing the vowel sound, a pattern called umlaut. Other examples include man → men and tooth → teeth.

4. How do I pronounce mice?

Mice is pronounced /maɪs/, which rhymes with ice and nice. The vowel sound is different from the singular mouse (/maʊs/), which rhymes with house.

Final Note

Remembering that the plural of mouse is mice will help you write and speak more accurately. This small but important rule appears in everyday conversation, professional emails, and technical writing. For more help with tricky plurals, explore our Common Plural Forms section. If you have questions about other irregular words, check our FAQ or contact us directly.