Smoke alarms in house. No smoking around children. No guns in the house .
Children are naturally curious.
They think guns are interesting and they frequently play with them. A doctor told me that she and her sister regularly found their father's disassembled, unloaded gun, put it together, loaded it, and played with it despite the fact that the father warned them they would be severely punished if they ever touched his gun. After playing with it, they carefully unloaded it, took it apart and returned the parts and bullets to their hiding places. The father never caught them. A word to the wise is sufficient.