I don't check my car at night but sometimes if I'm home alone at night and the dogs start barking at something outside (which I can't see since it's dark), I run to the front door and lock it. Most likely they are only barking at another dog that I can't hear, but it still creeps me out a bit at night.

I'm not a big night person, but my husband is which comes in handy if I want something- I can just send him to the store!