2. Bonfires In northern Ireland, it was customary for Druids to perform ritualistic ceremonies and make sacrifices to pacify their gods. The Celts would bring wood and start their Samhain(Pronounced Sow-en) bonfire or, fire festival, on the hilltop. Often, they would throw the bones of slaughtered cattle into the flames. The word "bonfire" is said to be derived from such "bone fires." Bonfires and sacrifices guaranteed that the sun would burn brightly after a long, dreary winter. It's common to witness hundreds of traditional bonfires in Ireland every year on Halloween Night.
3. Costumes Halloween costumes originated from the Celts when they lit huge bonfires and celebrated Samhain. They dressed up in elaborate animal skins and heads to disguise themselves as spirits and demons so that the real ones couldn't distinguish them as being human. Their ceremonies consisted of dancing, telling stories, and reading fortunes.
4. Jack-O-Lanterns The traditions of carving jack-o-lanterns originates with the Celts. A miserable man named Jack, tricked the devil. Unable to enter heaven or hell after his death, he was destined to roam the earth listlessly. Jack placed a piece of coal into a carved-out turnip and used it as a lantern to keep the evil spirits away. Today, pumpkins (which are easier to cut) are carved into jack-o-lanterns, lit and placed outside of doorways for the same purpose.
5. Trick or Treat The practice of dressing up in costumes and begging door to door for treats on holidays dates back to the Middle Ages and includes Christmas wassailing. Trick-or-treating resembles the late medieval practice of souling when poor folk would go door to door on Hallowmas , receiving food in return for prayers for the dead on All Saints Day . It originated in Ireland and Britain. The custom of wearing costumes and masks at Halloween goes back to Celtic traditions of attempting to copy the evil spirits or placate them, In Scotland for instance where the dead were impersonated by young men with masked, veiled or blackened faces, dressed in white.
6. UNICEF A popular tradition in America, trick or treating for UNICEF began in 1950, when Philadelphia youngsters decorated milk cartons and collected money to help less fortunate children. UNICEF increases public awareness and raises funds to provide health care, nutrition, immunizations and clean water, around the world.