Latchkey kids, the Coalition for Children explains, is a term that first arose during World War II when mothers went to work in factories while fathers were off at war. A latchkey kid is a child who is left at home unsupervised. Today, with many single-parent and dual-income families, Parents estimates that out of every 25 children in elementary school, one child goes home to an empty house. If your child is a latchkey kid, having a security company install a smart home monitoring system can both keep your child safe and help you parent while at work.