Why do we trick-or-treat on Halloween?

It's a tradition that children and families take part in every Halloween, with small candy bars and creative costumes spotted on every neighborhood street. But have you ever wondered why we go trick-or-treating?

There are several theories into what actually inspired the candy-giving custom we participate in today. Some believe the holiday has roots in the Celtic festival known as Samhain. The night before Samhain became All Hallows' Eve, and then later Halloween.

According to History.com, "during some Celtic celebrations of Samhain, villagers disguised themselves in costumes made of animal skins to drive away phantom visitors; banquet tables were prepared and edible offerings were left out to placate unwelcome spirits. In later centuries, people began dressing as ghosts, demons and other malevolent creatures, performing antics in exchange for food and drink."

In 1,000 A.D., Christianity had spread into Celtic lands and November 2 was established as "All Souls' Day," where "celebrations in England resembled Celtic commemorations of Samhain, complete with bonfires and masquerades." There started two traditions similar to trick-or-treating, known as "souling" and "guising."

"Poor people would visit the houses of wealthier families and receive pastries called soul cakes in exchange for a promise to pray for the souls of the homeowners' dead relatives," according to History.com. "Known as souling, the practice was later taken up by children, who would go from door to door asking for gifts such as food, money and ale."

Guising involved young people wearing costumes and accepting items from different homes, but didn't involve praying for people's souls like souling. Children instead would "sing a song, recite a poem, tell a joke or perform another sort of 'trick' before collecting their treat, which typically consisted of fruit, nuts or coins," according to History.com.

Some believe that Halloween also has roots in German-American holiday traditions. Belsnickling was one of these traditions where children would dress up in costumes "and then call on their neighbors to see if the adults could guess the identities of the disguised guests," according to Mental Floss. "In one version of the practice, the children were rewarded with food or other treats if no one could identify them."

Lisa Norton, author of Trick of Treat: A History of Halloween, wrote "this same custom appears in some early descriptions of trick-or-treat ... lending credence to the possibility that it derived from its Christmas cousin," according to Mental Floss.