[Trick or treat.]
Halloween is a holiday with very old traditions. In the old days, kids would carry bags and walk around their neighborhoods dressed like monsters and ghosts. They would knock on doors and when the door opened, they would yell, “Trick or treat!” and the person inside would put some candy in the bags. “Trick or treat” didn’t mean anything, it was just what you were supposed to say. Kids would never play tricks on people.
The Shelves are Stocked
For various reasons, most people don’t “trick or treat” like that anymore. They go to parties and have other group activities. It is safer.