Intercom system must be installed in your home, if you are leaving your kids alone at home. You can warn your kids not to open the door for any strangers. You can advise them to see through the video monitor, who is there at the door and then open only if it is you. Thus you can be relieved and do your works in a relief. Your kids can also feel that they are safe n secure inside. Also you can work with concentration in your office outside. Through intercom, you can always call and check the family members, especially kids and elder person.