Random Toys?!?

So this morning at 4:00am I heard an odd noise over the baby monitor. "Old Mcdonald" loud and clear. Not Danya but one of her toys. At first I thought where did that noise come from? I couldn't remember any toys that sang that song, so I was really confused in my sleep enduced haze. I jumped up and quickly went to her room. Danya was out cold so I didn't go looking for the toy, but it stopped so I went back to sleep. It didn't go off again all night or all day. When she woke up I pulled it off the shelf. Old Mcdonald is a page in the center of a Vtech book. I have no idea how it started playing. Odd huh?