The Birds and the ... Trees?

After spending all afternoon at a park with a group of Moms and their kids (and several babies), we were driving home. (The car seems to be where all my "deep" conversations with my kids happen.) Mr. T asked me if I would "buy" him a baby. A bit confused, I asked him to clarify whether he meant a real baby or a doll baby. Not a bit flustered he answered that he meant a REAL baby, a baby brother, of course! I told him that unfortunately that's not something you can buy. "But where do babies come from?" he asked, quite urgently. Since he's not my oldest, and I've been through this before, I calmly answered with a question to scope out his knowledge, "Where do you think babies come from?" Without a second to spare he replied, "They grow on trees up high with the leaves. When they're all done they fall out." I was quite interested in his response... about a year ago he had an imaginary friend named "baby girl" who was always climbing up trees! Who knows?! I clarified a bit, pointing out exactly where babies do grow (Mommies' tummies actually)... but he was dead set on his tree answer. He did however have one remaining question: "How do the babies get in the trees?" I wonder if I'll ever have this Mommy thing figured out!!!