I know it's not for everyone (especially people renting) but recently when I expanded and redid my house, I ran wiring (in my case, cat5e) for my camera system to every bedroom. This way, when I do have a baby or little child with a babysitter, I could just plug in a camera and see what's happening (plus I could use it as a baby monitor because I have screens in my kitchen, home office, and bedroom). I highly recommend doing this, when possible.