This question should be answered by your parents or your biology teacher. Not by anyone in some online game. It is a process of procreation. Male and female bodies are made very differently for specific purposes. Scientifically speaking, it is the insemination of the egg that starts the wondrous miracle called pregnancy. This powerful merge will "evolve" the egg into an embryo. The embryo then implants itself to a very special place! The baby is held inside this special organ in a female body that the baby can feed and play and wiggle about. Ahh... The wonders! It is amazing how wonderful nature is!
._. Mommy said babies come from eBay. They just have a really long shipping process of around 9 months. .-.