The old ploy goes something like this: They ring the doorbell to make sure nobody is home. If someone answers, they ask if someone is home. You say the person doesn’t live there and they leave. But if nobody answers they break in and rob you.
MarkTwain has posted a lot of articles about armed people who don’t answer the door and then when thy guys break in they get shot and/or killed.
"Crazy" Joe Devola (Seinfeld) said he never locked his doors - liked to "encourage" intruders....