[quote=Legend]
Get one. It's so helpful. And an electronic lock instead of a dumb key lock. You said the exact question?
[/quote]

To be fair, we once left the house and forgot that the front door was wide open, and when we came back after an hour we discovered that it was open. Thank God, nothing was stolen, although somebody could have just walked in at any time and took things out.

TL;DR:
God is our alarm system.