I started teaching my son about guns and the safe handling, proper use, dis assembly /cleaning and safe storage when he was 4yrs old and did the same with my daughter. I would take them shooting 1 to 5 times a week and I never worried about my kids getting into my guns. My son is now in the Army gong through Scout tryouts and then Ranger school and my daughter is in college to be an Orthopedic Surgeon and attends weapons classes with me.
The morale of the story: Teach the kids about weapons and there proper use and take them out and shoot.