In Manila, capital of the Philippines, pets get in on the action too. An annual costume contest aims to raise funds for animal welfare groups.
By the 11th century, this had been adapted by the Church into a tradition called souling, which is seen as being the origin of trick-or-treating. Children go door-to-door, asking for soul cakes in exchange for praying for the souls of friends and relatives.
The tradition of Halloween was carried to America by the immigrating Europeans. Some of the traditions changed a little, though. For example, on Halloween in Europe some people would carry lanterns made from turnips. In America, pumpkins were more common. So people began putting candles inside them and using them as lanterns. That is why you see Jack o lanterns today.