Halloween originated as a native American tradition where people would disguise themselves as spirits to avoid recognition by evil souls. They would light fires to ward off spirits. The modern tradition of children dressing up and going door-to-door asking for candy stems from past customs of sacrificing objects to calm spirits. Now, people carve pumpkins and children go house to house saying "trick or treat" to receive sweets, playing pranks if they don't get candy. Teenagers now celebrate by partying at discos.