Signs that an opossum is orphaned: Opossums are marsupials, so mothers will carry their babies in their pouch. If a mother opossum has been killed, check to see if the babies are alive in the mothers pouch. Baby opossums that are under 7 inches without the tail need their mother. If a baby opossum is alone without their mother and the mother does not return to retrieve the baby, the baby is weak or thin, if the baby shows any signs of injury or illness, or the mother is clearly dead, contact a wildlife rehabilitator.