Why do people feel safe when they cover themselves with their covers?

[701]

or get scared if say, they're sleeping on a couch and face the couch, thinking some monster or something is going to get them.

where is the underlying psychology of this? I've noticed many other things as well, that humans do that they don't tell people since they don't think it's that important, but then when you're on FB or Twitter, you found out many people did/do it too.

why?

[Jeff]

Because you can't see me when I hide under my covers. Duh. And if you can't see me, you can't eat me.