What is why wrap foil around door knob when alone?

It is recommended to wrap foil around a door knob when alone to prevent someone from unlocking the door from the outside using a tool such as a credit card or a wire. Wrapping the knob with foil makes it harder for the tool to gain traction and push down the latch, making it more difficult to unlock from the outside. This can provide an extra layer of security for those who live alone or are concerned about someone gaining entry to their home. However, it should be noted that this method is not foolproof and does not substitute for proper locks and security measures.