A couple of weeks ago, I noticed that Charlie's eyebrows were starting to darken. They had been practically nonexistent blond before. Then, I noticed a strange mark on his lower belly. I thought what has he gotten on him? Then I realized what it was--his birthmark! I had been told that his melanin production wouldn't kick in until he was 4 or 5 months old (thanks Gay!). And I guess that's what made his birthmark darken.