I have uncles that are identical twins, one is right handed and the other left handed. They used to get put in different classes in school so they wouldn't cause trouble. They figured out that they only had to study for half the tests and would each take the same test twice by switching shirts between classes. They are also both reasonably ambidextrous and would write with either hand. All went will until one brought his baseball glove in after recess and the teacher noticed it was for the wrong hand. Neither would admit how long they had been pulling the scheme but everyone suspected was the better part of a year.