Have you ever arrived home to discover your front door was unlocked and wide open? I have, twice now. Granted, this time I had a storm door screen that was closed in front of it, but that was unlocked too.
I was only gone for 45 minutes which is better than all day, but still. As I was packing us up to leave (diaper, wipes, sippy cup, shoes, keys, purse) Superman called me and I stayed on the phone with him until just before I drove away, completely forgetting that I had not locked the front door and pulled it shut behind me. So it was just how I left it when I returned.
Even though I was fairly certain I had done this myself (though I honestly couldn't remember, thanks a lot BABY) I put K on my hip and dialed 911 on my cell phone with the other hand. (It should have been the house phone but the house phone was too far into the house.) My thumb was poised over the "call" button in case I encountered anything. I entered cautiously and carefully looked over each room on my way directly to the backyard, where I keep two large dogs with large teeth. I am very thankful to have said dogs exactly for use in times like this. We all checked out the rest of the rooms in the house together and of course found nothing.
But it never hurts to be prepared.