Seems like it never fails. Every sunny, Saturday afternoon tends to come with a surprise caller or two at your doorstep. Between the Girl Scouts’ cookie drives, local kids selling candy bars for school, religious groups handing out invitations, and salespeople pounding down your door, you’re likely to open up to dozens of perfect strangers each year.

There’s nothing wrong with being neighborly. And there is certainly nothing wrong with a new box of Thin Mints. But if the person standing on your front porch is not easily identifiable, it’s best to be cautious about opening the door.

Burglars have come up with a clever way to pillage in broad daylight by acting like legitimate door-to-door salesmen or trades people. They usually present a bogus reason for showing up, such as an electrical problem or water issue you know nothing about. They will try to distract you with a sales pitch, or a closer look at some minor problem on the outside of your house.

Ideally, they will get you to walk with them outside, around the corner, to a spot where you can no longer see your front door. And while they have your attention there, the accomplices walk right in to help themselves to as much cash and small valuables as they can carry.

So how do you tell the difference between a Boy Scout and a burglar? Check the ID. Any reputable employee of a county office or a utility company will have a verifiable ID card on them at all times. If you’re not convinced by the card, call the company in question and double check that they sent someone to your home. If you’re alone, and unsure about the person who wants in, play it safe, and keep the door locked.