The Number Nobody Expects
In more than a third of American burglaries there's no forced entry at all: no pried window, no broken lock. The door just opened. Which means the single highest-leverage measure in home security is free: lock every door and window, every time, including when you're home and when you're gone for ten minutes.
A burglar runs the same math as any attacker: reward, effort, risk. And what they avoid most is people. An occupied house (or one that convincingly looks occupied) mostly doesn't get picked at all.
Layers, Not Gadgets
The evidence ranks the measures, and the basics beat the gadgets. The rule is the one you already know from this course: not one device. Layers, working together.
Lock it
Every exterior door and ground-floor window, every time. Real deadbolts on solid doors: the jamb and strike plate carry the load, not the brand of lock.
Light it & cut the cover
Exterior lights on sensors at the entries, and trim what hides your doors and windows. Concealed entries are where break-ins happen.
Look lived-in
Interior lights on timers, mail collected, garage closed. A house that reads occupied gets passed over; burglars often knock first to be sure no one's home.
And forget the movie version: slightly more burglaries happen in daylight than in darkness, because the driver isn't darkness, it's emptiness. Your house is alone all day, so the layers have to work unattended.
Same mindset, bigger object: layer the cost until the house isn't worth it. Not un-enterable. Expensive.