Guest somehow opened locked door

[Dave75]

My AirBnB is for a room only. It has it's own entrance from outside that guests use. They are not allowed in the main house. There is a door from the bedroom into the house hallway that I have a doorknob with a key style lock that locks from the house side. I keep this locked so the guests cannot enter the house.

I had a guest this weekend. At night I heard the hallway door being banged real loud, like she was trying to force it open. After she checked out this morning I looked and the doorknob was UNlocked! This is very odd. How could she have unlocked the door from the room side? From the room side there is a kwikset key lock on the doorknob (I don't mean one of those allan pin things I mean an actual key). The door handle was also full of hand smudge marks.

I felt really uneasy about the whole thing. Nothing was missing from my house - I don't keep valubles at home. It was just weird.

[David126]

A bolt on the inside may be more secure.

[Steve2743]

Locks are easy to bypass with enough knowledge or determination. Installing deadbolt would be a little more secure, but even that won't stop someone who's determined enough. 

[Kimberly139]

We had the same thing happen to us. AirBnB didn't apologize or do anything. Essentially our fault.

[Cynthia-and-Chris1]

@Kimberly139 Why would Airbnb need to apologize? They did nothing...

[Matthew285]

@Dave75, keyed door knobs are not very secure. They are really just designed to discourage people from casually entering a room.

(But, you already know that now...)

A good solid, properly installed deadbolt will increase your level of security. 

Also: make sure the door is sturdy.

Also: make sure the door frame is sturdy.

Also: avoid crazy guests.