I feel so stupid! I was reading with DD after school today and Wyatt was puttering around the main floor. I usually just let him explore, it's pretty baby-proofed. I could still here him, but granted it was quieter, so I figured he was behind the island in the kitchen or playing with the water cooler (his new favourite thing). So when we finished the book, I went to see what kind of mischief he was getting into. He was outside! I forgot that I had opened the patio door and just closed the screen door. He opened it and went outside onto the deck. No wonder I couldn't hear him too well.
So the next time you hear about young children wandering the streets at 2 am, it could very well be mine!