Does your cat actually eat their prey?
I have had cats all my life and found that they will generally eat small things they catch such as bugs but last night my cat caught a rodent (large mouse or small rat) and I think she ate it. I saw her munching away and the next time I looked it was gone. All that was left was a trace of blood and no sign of any body parts.
I know it is natural but I have never seen a pampered pet cat do this before which got my curiousity.