My little boy, Charlie, got one when he was born. He made it a girl named Twinkle. (If you give it a girl name, it will be a girl)
He played with it a lot when he was a toddler.
When he grew up, I didn't see a message to put the doll down so it could "explore the world". When he was doing a tea party and cleaning up, Twinkle bounced up and scared the life out of me since there was the music, and it really surprised me as I wasn't even watching. I had to pause to figure out what was going on, and I found out he was alive! I cheered and my sister walks in and says I'm weird.
I think it's funny how Twinkle walks (looks like like when sims have woohoo in public, lol) and runs. Its amusing how she's invisible on an another sim so it makes him look crazy. XD