a change in the lineup of DNA instructions. Sometimes, if the DNA changes, then the instructions for what to build will change, or mutate.
Natural Resistance

Clostridium difficile under a high-powered microscope. This bacteria is naturally resistant to many antibiotics, and causes people to have very bad diarrhea. Image by the CDC.
Mutant robots with six arms and a mind of their own are stuff of science ficiton, right? Scientists are challenging that idea by creating robo-mutants in the lab and seeing how they evolve.

How to Build a Monster
By Karla Moeller
Illustrated by Sabine Deviche

A Monster Story
By Karla Moeller
Illustrated by Sabine Deviche
There is an old story told to this day about a land filled with colorful monsters. In this mysterious world lived a family of monsters with a brother and sister, Matt and Matilda. Matt and Matilda shared everything – their monster toys, their monster candy, and even their monster dolls and trucks.