I think the rule would be to not put your gun in the night stand when you're not there! A well-motivated "BG" is going to take what he wants when I am not there, if he can get past the 4 dogs! After all, the whole idea of having a gun for your defense when you are are at home is to get to it as quickly as possible.
And also as others have said, do not underestimate the creativity of a child when it comes to discovering things in their universe. This comes from the father of 3 and grandfather of 7!