Halloween, October 31st. It is celebrated in many countries. Children & some adults wear costumes. Children go to people's homes. The people give them candy. Children say "Trick or treat!" to ask for candy. This comes from a threat. It means, "Give me a treat or I will play a trick on you." Children today usually do not do the tricks if they do not get treats. But some children still do mischief (playful pranks or things to make fun of people like putting toilet paper in trees or writing with soap on windows). In these countries Halloween is about ghosts, witches, goblins, and other scary things.