The Revolt of the Miniature Mutants
I Was a Sixth Grade Alien, Book 10
Written by Bruce Coville
from the back cover
When the hamsters in Ms. Weintraub's room start acting a little strange, everyone thinks the problem must be the alien vitamins Pleskit has been feeding them.
But even after Pleskit stops the vitamin treatments, the hamsters continue to get biggerand strongerand crankier.
Clearly, something else is at work, but what?
To answer that question, Tim and Pleskit will have to solve a mystery, track down an enemy, and defend themselves against a trio of the most dangerous hamsters the world has ever seen!