You're looking for your lost cat, after dark: do you just wander into someone's backyard with your flashlights or do knock on the door and maybe ask for permission?

Duh!

Some people did this to me a while ago. All of a sudden, out my window, I saw a man and a woman with flashlights creeping around my back yard and I went out there and asked them what the heck they were doing and they seemed, actually, kind of a little bent out of shape about it. “We’re just looking for our cat!”