L.E.
Use a large toob sock to put over top of the door and then pull the doors closed snuggly. It is too strong for them to open and then you don't have to install locks on doors that you do not want him to get into. This works for us. I also bring my son into the kitchen for example and fill the sick with 1/2 inch of water with lots of soap. He can splash and have a great time while I am cooking dinner or cleaning up other messes that he just made. It is great because if there are a couple of dirty dishes or even taking a couple of his dishes out of the dishwasher and putting them into the sick for him to wash he feels like he is being a big helper.