If want an amazing book, EcoMazes: 12 Earth Adventures is just what you are looking for. This book will walk you through 12 amazing environments. You'll go to the evergreen forests, the coral reefs, the frozen (aff) tundra, and the desert sands. You'll learn about each ecosystem all the while you are having fun doing mazes! While doing the mazes, make sure you keep your eyes open for the 350 hidden animals (for mom and dad: there is an answer key in the back of the book so don't worry about any meltdowns when they can't find everything). Each maze will tell you which hidden animals to look for.
EcoMazes: 12 Earth Adventures makes science fun. It'll open that door for you and your kids can figure out what ecosystems they have visited. There's a lot more out there than are included in this book, and they may want to research those too!