Baby or Toddler?

At what moment precisely does a baby become a toddler? Is it when he takes his first step? Or when he climbs up and then falls off the kitchen table? Maybe it's when he no longer wants to snuggle into your chest when he's tired.

My son is becoming lots more work. As a baby, he slept and ate and smiled and laughed. Now he climbs and sometimes falls. He empties out drawers. He makes messes. He makes funny noises and tries to mimic his Dad. Yesterday, after I got him dressed he went to the front door thinking that we were going somewhere. We weren't.

He can climb up the bunk bed ladder. He stands on his tiptoes and plays the piano. He tries to feed himself. He plays with his Dad's cell phone. He likes to poke his head into the washing machine.

Two days ago I found his Dad's cell phone in our front-loading washer after I'd just washed a load of towels. It was soaking wet and totally ruined.

I think we have a toddler.