When other kids come into the home, having a child who knows to leave guns alone unless they're with a responsible adult can defuse a potentially catastrophic situation. Securely storing your guns and ammunition when not in use is mandatory. Installing a trigger lock and storing guns in a locked cabinet will help preclude unauthorized access. If a critical part of the gun is removed and stored separately, it is more secure. Those with several guns should seriously consider a safe.
Many companies offer models with combination locks, interlocking bolts, and optional fireproofing.
Most are configured to store both long arms and handguns. Safes will stop the amateur burglar or kids, but not the professional burglar. Safe handling and securely storing firearms are so important that the discussion bears repeating.