While not as exciting as Micro Monsters or some of the other DK Readers titles, this book is still in our boys' bookshelf. We moved to a new neighborhood where there are several resident squirrels. Our boys wanted to know more about them and why they live in trees.
This book is perfect for kids aged up to 6. I like the pictures, which generates a lot of questions at bedtime.
This is another great DK Reader. It is for level 2 readers, but you can read it to your children (3-5 years). It is very intersting and takes kids through the life of a tree, parts, oldest tree, etc. I learned some things too!
My daughter is in the first grade and reads as part of her homework. This is ideal for her, easy enough to read, but still has those challenging words for her to learn. Also, it is very informative about the life of tree. It is really well written for the age, it also makes learning about nature fun.