Sometimes they do bring the prey to show you, but sometimes they don't. I have seen cats eat mice or rats. When they do eat it is mostly the same. The cat chews and crunches on the tip of the tail first, then the hinds always chewing and crunching until they get to the head. With the rats they sometimes leave the upper front teeth, but with the smaller mouse they eat it all I believe. Also look for signs of the mouse or rat hair. The hair usually can't get digested that fast so it goes right through.
If you keep on seeing mouse or rat dung then your Edgar still has work to do. :)