In over 4 years of doing childcare, I've only ever had one parent ask for it. She also wanted to see in every room, closet, drawer and cupboards...then asked for a tour of upstairs too! It was awkward, I wasn't sure if it was still an interview or if she wanted to buy my house? I even asked my man if he had a crazy ex named ______! lol
I have wondered the same about asking references from the parents too, since I give them my references. It would be nice to know why they want to jump ship in their current dcp!