I did that for years, but if Mingo isn't around when I need to go out, I don't look for him. He's my door-dasher. Generally, I know they're safe in the house and I don't worry about them. However, I had a plumber here last week, and I've just noticed that a tile in the dropped basement ceiling is askew and near the stairs where a cat could get into it. Just imagine having a cat hiding in a dropped ceiling! Gotta fix it soon!