Some marsupials include the koala , kangaroo , and the numbat . Before birth, the young are nourished through a placenta. The placenta is a specialized embryonic organ that is attached the mother's uterus and delivers oxygen and nutrients to the young. Most mammals are placental mammals, like cats, dogs, horses, and people. Diet Mammals have to eat a lot to maintain their high body temperature.
Diets vary from genus to genus.
Loudest mammal - the Blue Whale . The second loudest is the Howler Monkey . As stated in our privacy policy , we fully respect your privacy and will not use your e-mail address for any purpose other than the newsletter subscription. For a fantastic T. rex Puppet, click here . Search the Web with GoTo ZOOM is a registered trademark of WGBH Educational Foundation.