How the burglars able to break in the house and stealing without being notice by the owner?

Sleep like death? Or voodoo stuffs? Or they just got really really lucky?

Most of the burglarly didn't end with violent. The victims are fine didn't harm except they losing belongings, money, cards of course.

How can no one notice or even wake up suddenly when there is intruders breaking their home? Unless the door and the windows aren't locked well.