Most people know what to do when they open their front doors on Oct. 31st and find themselves confronted by a vampire, a mummy and a werewolf: they give them some candy.
According to CU-Boulder Professor Michael Preston, the history of trick-or-treating is an interesting and varied one. And today, "There's much more adult humor. There is an awful lot of cross-dressing," said Preston, as opposed to past generations, when there was not as much emphasis on disguise. For example: