
Halloween has its origins in the ancient Celtic festival known as Samhain (Irish pronunciation: [ËsË aunʲ]; from the Old Irish samain). The festival of Samhain is a celebration of the end of the harvest season in Gaelic culture, and is sometimes regarded as the "Celtic New Year". Traditionally, the festival was a time used by the ancient pagans to take stock of supplies and slaughter livestock for winter stores. The ancient Gaels believed that on October 31, now known as Halloween, the boundary between the alive and the deceased dissolved, and the dead become dangerous for the living by causing problems such as sickness or damaged crops. The festivals would frequently involve bonfires, where the bones of slaughtered livestock were thrown. Costumes and masks were also worn at the festivals in an attempt to mimic the evil spirits or placate them.
Halloween was perceived as the night during which the division between the world of the living and the otherworld was blurred so spirits of the dead and inhabitants from the underworld were able to walk free on the earth. It was believed necessary to dress as a spirit or otherworldly creature when venturing outdoors to blend in, and this is where dressing in such a manner for Halloween comes from. This gradually evolved into trick-or-treating because children would knock on their neighbours' doors, in order to gather fruit, nuts, and sweets for the Halloween festival. Salt was once sprinkled in the hair of the children to protect against evil spirits.