How babies are "made"

Last night as Seth was getting to sleep he asked me about "babies". He wanted to know how they got out of mommies bellies? The moment all mommies wait for! I told him that most mommies went to the hospital and they got their babies there (hoping it would be enough). He nodded understandingly and said, "Do they cut them out?" I said, "Sometimes". He thinking he had it all understood said, "And when they plant them they put the dirt in the mommies stomach and pat in all down?" Okay, now I was at a loss!! hummm....I simply replied, "no dirt". He nodded again, that nod of understanding a 5 year old has (that no one on earth can follow)! Thankfully he was satisfied! Although I really hope he does not try to explain the wonder of birth to anyone! lol