Halloween is a holiday celebrated on the 31st of October. Children (and adults) dress in costumes that range from cute to bizarre and even frightening. Children traditionally visit the houses of their friends and relations, knock on doors and call out "trick or treat!" If the people within the home do not respond with a treat then the children (aka trick-or-treators) respond with a trick. Common tricks include using eggs and toilet paper to decorate houses and trees. Other Halloween activities include carving pumpkins, bobbing for apples and baking pumpkin pies. It is, in many ways, derivative of old pagan holidays celebrating the change of summer into fall.