He's HOW old?

Seriously - how is Declan already 11 months old? He is our serious guy who usually only smiles for Mama, Daddy or one of his silly siblings. He can get back to sitting from his belly if he is on carpet and I'm pretty sure he has mastered teleporting, because every time I turn around he is somewhere other then where I left him but I have yet to see him actually crawl or scoot with purpose. He's a sneaky guy!