From the fantastic Wells of Knowledge nonfiction picture book science series, What’s Smaller Than a Pygmy Shrew? by Robert E. Wells (Albert Whitman, 1995) teaches about microscopic creatures for young readers. Beginning with a small creature, this book encourages child readers to consider even smaller creatures, including bacteria and the size of an atoms.
The book has fantastic variety of creatures in the illustrations, and I love the realistic but familiar colored pencil style illustrations. There is a lot of educational text on each page, but it would be great for middle elementary children, especially read one-on-one. I find the text highly readable with nice sentence structure and a familiar casual tone.