how comes some animal male or female can have baby but us humans only woman can have babys

Question: how comes some animal male or female can have baby but us humans only woman can have babys
- Keywords:
  baby,
  female,
  gender,
  male,
  reproduction
Asked by phillipa1 to Jo, Kevin, Louise, Valeria on 21 Jun 2012.
- Kevin Mahon answered on 21 Jun 2012:
  
  Well firstly I should point out this is very, very rare – only one groups of animals have male pregnancy, the Syngnathidae (piipefish and seahorses).
  
  It is still considered one of the greatest mysteries in the fish world! We’re not certain yet why this evolved (we know when it evolved). Current work has led reserachers to believe it may have started out as the by-product of a gene that regulates the liver and kidneys but definitive answers are still forthcoming!
- Joanna Cruden answered on 21 Jun 2012:
  
  I am not sure any male can produce the eggs, the female sea horse (sensibly) lays her eggs in the pouch of stomach of the male and he fertilises them and carries the baby.
  
  For all mammals the female is the one who has the babies and we are mammals.

Question: how comes some animal male or female can have baby but us humans only woman can have babys