You wouldn't provide your child with a screwdriver to play with around your home so STOP inserting a tool into your sockets that could potentially be the cause of serious harm or even death of your child. They are far more intelligent and able than we give them credit for.
If you know anyone with children or you have friends or family that look after your children then be sure that they have seen this video and understand the DANGER involved with using an Electrical Socket Cover.