Human reproduction is when grown-up humans who can make babies (like mommies and daddies) come together to make a new baby. It starts when a grown-up mommy and daddy join their special parts together. This helps the dad give the mom a tiny seed called a sperm. The mom's body takes this tiny sperm and, if it is the right time, it grows and becomes a bigger seed, called an egg. Then the egg and the sperm meet together and make a new baby. The new baby grows inside the mommy's body until it is ready to come out, which is called being born!