Among the best characteristics of mammals that include the presence of hair or fur on the skin and mammary glands in the females that secrete milk is they give birth to their live young instead of laying eggs. However, there is and exception to this. Of the 21 orders of the Mammalia class, one order is so classified for the reproductive nature of its species to lay eggs rather than live births. This is the order Monotremata.
The Egg-Laying Mammals
Among the best characteristics of mammals that include the presence of hair or fur on the skin and mammary glands in the females that secrete milk is they give birth to their live young instead of laying eggs. However, there is and exception to this. Of the 21 orders of the Mammalia class, one order is so classified for the reproductive nature of its species to lay eggs rather than live births. This is the order Monotremata.