My cat loves hunting. We have had a variety of mostly dead creatures, but he mainly brings in mice now. He seems to eat most of the mouse but always leaves a bit in his empty food bowl - generally a kidney/ some guts or a leg. Why??? leave a bit - is it a present for me?! He doesn't come back for it. It isn't always the same bit so can't be taste? I don't mind too much as it is easy to tip out then clean his bowl, but I'm curious!