Mrs. Frisby and the Rats of NIMH/YMMV

Everything About Fiction You Never Wanted to Know.


  • Adaptation Displacement: Many people who've seen the movie aren't even aware this book exists.
  • Inferred Holocaust: The rats of NIMH increased from a group of 20 rats to 115 rats in only five years. Thorn valley can sustain an estimated capacity of 2000 rats. If the rat population continues to grow at the same rate (about 142% a year), they will hit their maximum sustainable population density in only 8 years. Normally the fact that rats breed like... well rats, is remedied by predation and their own short lifespans, but the rats of NIMH are too smart to prey on and since they've been uplifted, their lifespans are many, many times that of an ordinary rat. These rats are either going to have to invent the world's tiniest condoms or the earth will be entirely overrun by hyper-intelligent rats in less than fifty years. (The sequels indicate that many of the mated Thorn Valley couples have limited offspring, and that many rats choose to focus on scientific pursuits for some years before even considering a family. Timothy and Racso's best friend Christopher often bemoans his only-child status.)