I never, ever, ever, answer the door unarmed.
Both my font and back doors have storm/screen conbination doors on the outside. The house was previously owned by a fairly wealthy business owner and he hed them installed.
when I open the inside door, even with the screen door exposed...you can't get through....an extremely strong, lockable security door on the outside (I do have a gun nearby however, but the doors must have cost a pretty penny when installed!!!!....Thanks previous owner!!!