What is wrap foil around door knobs when alone?

Wrapping aluminum foil around door knobs when alone is a safety measure to prevent intruders from opening the door. It is a low-cost and easy DIY hack that can provide an added layer of protection for people who live alone or feel vulnerable in their home. The foil acts as an alarm system by making a noise when someone tries to turn the knob, giving the homeowner time to react and take necessary precautions. However, this method is not foolproof and can be easily bypassed by experienced intruders. It is important to still have a proper locking mechanism installed and to always take precautionary measures when living alone.