With a few exceptions, mammals are animals that have fur/hair on their bodies, regulate their body temperature, nourish their young with milk and they give birth to live young.
The National Geographic Book of Mammals , by National Geographic Society, is a great resource for children. Presented in a single volume, this book is filled with marvelous photographs of over 500 animals in their natural habitat.  Provides an illustrated introduction to the world's mammals, arranged alphabetically from aardvark to zorilla (common name striped polecat)  describing their physical characteristics, habits, and natural environment.
The book list that follows consists of picture books. Although, these books are not factual,but they provide a fun way for children to relate to the subject matter.
Awkward Aardvark  Mwalimu
Night after Night, Aardvark's snoring keeps the other animals awake. Something has got to be done! Mongoose calls everyone together to help, but it's not until the termites  get involved that the problem is solved.
The Awful Aardvarks Shop for School  Reeve Lindbergh
No display table goes untouched or sale rack unruffled when the awful Aardvarks storm the mall with their back-to-school list in hand. From sporting goods to school supplies, toys, clothing and books, the Aardvarks create some predictably happy havoc with storeowners and shoppers alike.
Trick or Treat, Old Armadillo Larry Dane Brimner
Halloween is full of surprises. Old Armadillo hears the distant sound of laugher and voices as children scamper from house to house. He sets jack-o'-lanterns on the edges of the flagstones. Inside his casita  , he settles down before the fire with a mug of hot cocoa and his favorite book of ghost stories, waiting for goblins, pirates, and princesses to come knocking. He is ready for Halloween. Old Armadillo waits and waits and wonders if he ever will be visited by trick-or-treaters. Meanwhile, outside, Roadrunner, Bear, Peccary , and other friends are planning a Halloween surprise for Old Armadillo. But when friends knock on his door, they find another surprise in store. Includes a glossary of Spanish words.
A blue norther's a-blowing', and Miss Billie Armadilly is hankering  to make a pot of chili! Only she needs to fix it all by herself because Tex the tarantula, Mackie the bluebird, and Taffy the horned toad are too busy to lend a hand.
Nightsong  Ari Berk
Chiro, a young bat, is nervous  about flying into the world for the first time without his mother, especially on a very dark night, but he soon learns to rely on his "song" to find his way and stay safe.
Bat's Big Game Margaret Read MacDonald
The Animals and Birds are getting ready for the big game. Bat wants to WIN. The Animals look strong and fast, so Bat picks that side. But when the Animals fall behind, Bat switches to the Bird team--doesn't a bat have wings? Maybe the Birds will win!
Termites on a Stick : A Chimp Learns to Use a Tool  Michèle Coxon.
Simple text and realistic paintings follow Little Chimp and his mother through a day in which the youngster emulates  his mother's use of a handy tool.
Me... Jane Patrick McDonnell.
Holding her stuffed toy chimpanzee, young Jane Goodall observes nature, reads Tarzan books, and dreams of living in Africa and helping animals. Includes biographical information on the prominent zoologist. 
What to Do If an Elephant Stands on Your Foot  Michelle Robinson
A witty  jungle romp for the adventurer in every kid Safari etiquette  can be tricky. Fortunately,  our trusty narrator can help. Sort of. From what to do if an elephant stands on your foot ("Keep calm. Panicking  will only startle it!") to how to escape the attentions of a crocodile ("Well? What are you waiting for? Wave your arms around and shout for help!"), our plucky guide leads our unlucky hero on a jungle adventure, barely avoiding tigers, a rhino, snakes, and--uh-oh. What's that? Well thank heavens the monkeys are friendly at least!
The Thingamabob  Il Sung Na.
One day, he found the thingamabob. He had no idea what it was or where it came from. . . . So begins the story of a curious elephant and a mysterious  red object. But what is it?! When none of his friends can tell him, the little elephant decides to experiment . He thinks: Maybe I can fly with it? (Maybe not.) Maybe I can sail in it? (Maybe not.) Maybe I can hide behind it? (Maybe not.) Nothing seems to work, until big drops of rain begin to fall. The little elephant does not want to get wet. Luckily, with the thingamabob (an umbrella), he does not need to get wet! With bright, adorable illustrations and a simple, playful text, Il Sung Na captures the excitement of making and sharing an unexpected discovery.
Marsupial Sue  John Lithgow
If you're a Kangaroo through and through, Just do what Kangaroos do. Young Sue really doesn't like being a kangaroo, so she goes off to find something better. First she tries climbing the trees like a koala, but that doesn't work. Then she wades into the sea like a platypus , but that's no good either. Finally, Sue joins up with some bouncy, jouncy wallabies ...and discovers that being a kangaroo isn't so bad, after all. Using a jaunty waltz rhythm, actor, comedian, and best-selling author John Lithgow reassures children that they can be happy with who they are. For listening or singing along, a CD of a John Lithgow performance of Marsupial Sue and an instrumental version is included with this book, as is the score of the song.