We are using Apologia Zoology and we on the first unit which is Birds. You don’t really need these book as a spine though. My Aunt (the Scientist) purchased these as a request from us. They are Charlotte Mason style Science books. Essentially they are written like a story. There are a lot of opportunities for reviews questions and notebooking. Vocabulary words are in bold throughout the text if that is important to you. If I could get my son to write more I would probably created a vocabulary book or something along that lines. But, I’ll take what I can get. Apologia offers free notebook pages, so we are going to use some of those plus other stuff we find on the internet. I like that we can just read the book and move on that week if need be. As the boys get older and are demanding more information I’m finding it nice to have spines for learning.
You could simply use books from the library and crated your own unit.
The Land of All Things Lewis 