I did have a problem with Cap not eating the mice, though he showed interested in them. In the end it turned out to be that they weren't getting hot enough and I needed a new way to heat 'em. He recognized the smell, he recognized the movement, but the heat was wrong, so he would observe them briefly, then turn away.

Before you go looking for that, make sure you've done everything else on the list. I'm still kind of a newbie.