All mammals have 3 things in common:
Most mammals give birth to live young, but three species of mammals called monotremes (the platypus and two echidna species) lay eggs. Almost all mammals are endothermic, or "warm-blooded" (they are able to maintain their body temperature) but there is one species that can be considered ectothermic, or "cold-blooded" (its body temperature varies with the ambient temperature). Find out which one.
Scientists at the National Zoo discovered that golden lion tamarins must be kept in family groups to reproduce successfully. About two weeks after the birth of offspring (usually twins), the father and siblings begin helping the mother carry the infants. more
In wet conditions, algae grow in the spongy fur of sloths, helping to camouflage them in the trees of Latin American rain forests. Sloths, such as the two-toed sloth, live on low-energy leafy diets; they conserve energy by moving slowly, hanging rather than standing, and lowering their body temperatures at night. more
A female common tree shrew gives birth to blind, helpless young in a nest separate from her own. She visits the nest only once every two days, each time nursing the infants for just five to ten minutes. After about a month, the young leave the nest and become independent. more