Generally they do. Occasionally I'll have to lift up their hide to get their attention. See what works best for you. If they don't seem to know food is there, go ahead and take out their hide. The only reason I suggest keeping them covered is because I had a problem feeder who it was obvious felt insecure when I took the lid off to feed her. I stuck the food in with tongs while keeping her lid on and she gobbled it right up (I did have to remove her hide to get her to come out, though).
After the first couple of feeds, my snakes no longer felt insecure when I removed their lid. Keeping the lid on is, at least in my experience, only necessary the first few times for tricky eaters.
While dangling is very helpful, too forceful of dangling can scare the snake off. Just a tiny bit of wiggling, or even laying the rat down and nudging it with tongs, works best to simulate movement of the rat.
Its to a lot to digest (get it?) but it's extremely rewarding so keep at it!