My son had magnifying glasses. We showed him how to kindle a fire with one. When he was old enough, we also showed his best friend and showed them how to be safe, on the concrete, burning a hole in one leaf. The boys went out front to get something from my car and his friend stopped and started a fire in a leaf pile at the curb about a foot from my car! Thankfully I came tracking them down and snuffed it out immediately. The boy with the stick reminds me so much of my son's friend...