Mrs. Frisby and the Rats of NIMH
by Robert C. O'Brien
- Lexile
- 790L
- Grade range
- Grades 4–6
- Age range
- Ages 9–12
- Pages
- 233
- First published
- 1971
- Genre
- Middle Grade Fiction
- ISBN-13
- 9780689710681
About this book
A widowed field mouse must move her family before the farmer plows over her home, and turns for help to a colony of intelligent rats who escaped a laboratory. O'Brien's Newbery Medal novel is a 4th-6th grade staple with strong thematic depth.
Themes
- family
- courage
- science and ethics
- intelligence
- legacy
Content notes
- animal testing
- peril
Common Sense Media recommends age 9+.
Where this book is assigned
Common Core State Standards (ELA)
- required· 5th gradesource: CCSS ELA Appendix B, grades 4-5 Newbery Medal
- recommended· 6th gradesource: CCSS ELA Appendix B, grades 6-8 exemplar
Similar grade-level books
Common questions
- What grade level is Mrs. Frisby and the Rats of NIMH?
- Mrs. Frisby and the Rats of NIMH is most commonly assigned in US schools in grades 4–6, with a Lexile measure of 790L. Specific grade placement varies by curriculum — AP Literature and IB English Literature typically use it in grades 11-12.
- What is the Lexile level of Mrs. Frisby and the Rats of NIMH?
- Mrs. Frisby and the Rats of NIMH has a Lexile measure of 790L according to MetaMetrics. Lexile measures text complexity, not content maturity — check the grade range and content notes separately for age-appropriateness.
- What curricula assign Mrs. Frisby and the Rats of NIMH?
- Mrs. Frisby and the Rats of NIMH appears on reading lists for Common Core State Standards (ELA). Each assignment on this site links to its primary-source citation.
- Is Mrs. Frisby and the Rats of NIMH banned in schools?
- Mrs. Frisby and the Rats of NIMH does not appear in PEN America's Index of School Book Bans 2022-2024. No documented multi-district removals on record, but individual districts may challenge titles locally.
- What themes does Mrs. Frisby and the Rats of NIMH explore?
- Central themes in Mrs. Frisby and the Rats of NIMH include family, courage, science and ethics, intelligence, legacy. These themes match how the book is discussed in most curriculum guides and AP Literature prompts.