I bought this for my son's fifth birthday six months ago.
I have read it to him approximately ninety jillion times since then. He loves it.
He was unfamiliar with some of the words (saliva, jaws, and shrubs are words he didn't know, off the top of my head), but instead of being confusing, this just helped us expand his vocabulary. The pictures are beautiful and big. His favorite part is reading about the predators of each bug.
I bought it because he liked to catch fireflies. Now, he's much more interested in insects and other 'bugs'. His kindergarten had a 'Dress as your favorite character from a book and bring the book to share', day, and he brought this book. We made him a roly-poly costume to wear that day.
10/10 - took a mild interest on the part of my kid and helped turn it into a bigger interest. I would definitely buy this book again.