Oh, mice will eat it! It's one of the only things I don't find uneaten in my mouse tubs.

And the advantage is Protein! Giving rodents good protein and calcium can keep them from cannibalizing their babies and just makes them healthier.
Make sure to use senior formula foods, tho, as others can have too much protein. There's a proper percentage, but I forgot. Maybe Becky will chime in with it.