Halloween is a time for tricks and treats. On this day, children get dressed up and go door to door asking for treats, which is usually candy. But they can also get a trick, which usually entails someone scaring or pulling a prank on them. But even though you may believe you know everything about Halloween, join me as we dive deep in this horrific holiday and learn 5 facts you may not have known about it.

1. It was the baby boomers who made trick or treating what it is today.

A movement to start trick or treating began in the late 1920s and early 30s. But, according to Susan Whiteside of the National Confectioners Association, it wasn’t until post-World War II and the end of sugar rationing that it really took off. As a result, baby boomers are the first generation to have trick or treated both as kids and also grandparents.

2. Vampires legends come from corpses dug up in the Middle Ages.

People visiting loved ones on their deathbeds picked up lethal diseases like tuberculosis and mysteriously died weeks later. Without modern epidemiology, it was unknown how the illnesses had spread.

Occasionally the bodies were dug up. And the stages a body goes through as it decomposes combined with the mysteries of the disease itself may have given rise to common vampire and monster traits.

3. Weird party games helped secularize Halloween

Halloween is associated with costumes, candy, mischief and spooky, supernatural phenomena. But that wasn’t always the case, according to Nicholas Rogers, a history professor at York University and author of “Halloween: From Pagan Ritual to Party Night.”

Halloween falls on the eve of All Saints’ Day within the Roman Catholic Church. But after Scottish and Irish immigrants moved to the United States and Canada in the late 1800s, it started to lose its Christian connotations. As the holiday became more of a fixture in popular culture, it became more commercialized and secular, Rogers said. People played games to foretell the future, including interpreting the shape of uprooted cabbage stems to predict a future husband’s character or finding a potato with a hidden ring or sixpence that guaranteed a year of good luck.

4. Pumpkin carving was an Irish tradition that helped save small American farms

Before the 19th century, the Irish carved turnips into lanterns during the Celtic festival of Samhain, believing that the light would keep the spirits away from their homes. When waves of Irish immigrants moved into American cities, the pumpkin became a natural substitute. Pumpkins had always been a symbol of American abundance, growing out of control like weeds. But by the 18th and 19th century, they weren’t a popular food, says Cindy Ott, author of “Pumpkin: The Curious History of an American Icon.” Irish immigrants brought the pumpkins inside as decoration, giving them faces and spooky personas as part of a parlor game.

5. Originally, you had to dance for your “treat.”

Most experts trace trick-or-treating to the European practice of “mumming,” or “guising,” in which costume-wearing participants would go door-to-door performing choreographed dances, songs and plays in exchange for treats. In some early versions of trick-or-treating, men paraded door-to-door, and boys often followed, begging for coins. Most of these early trick-or-treaters were poor and actually needed the money, but wealthy children also joined in the fun. Door-to-door “begging” was mostly stopped in the 1930s, but re-emerged later in the century to distract kids from pulling Halloween pranks.