There are three groups of mammals; egg-laying mammals ,pouched mammals and placental mammals. These three types of mammals are different for one main reason: reproductive methods. The egg-laying mammals lay eggs. The pouched mammals give birth to underdeveloped offspring. The offspring then spends time in the mother's pouch, and mature. The placental mammals keep their offspring inside them then give birth to a fully developed offspring.

2. The anteaters and spiny ant eaters were two separate kinds of mammals. the Spiny anteater lays eggs to reproduce, the anteater does not.

3. Two pouched mammals are Kangaroos and Koalas. Their young develop in pouches.

4. Mammary Glands are glands on the female mammal. They produce milk for the offspring to drink.

5. There are ten types of placental mammals. Here were their names and characteristics.

Name Characteristic1. Toothless No teeth2. Water dwelling Live in water3. Trunk Nosed Have trunks as noses4. Rodent like Similar to rodents5. Insect Eating Insects as food source6. Flying Flying7 Primates Ape like8 Gnawing Eat by Gnawing9 Flesh Eating Carnivorous10 Even hooved Feet were hooves with even sides.

6. Whales were considered mammals for three reasons. First of all, they bear live young. Secondly they must surface for air. Lastly, they feed their young with mammary glands.7. Sharp teeth help predators to devour their prey.

8. Primates were considered the smartest animals because they use their