Apple

A word about using bait: if you do pop down a bit of apple to make your voles pause and pose and that apple doesn't get eaten, don't leave it out when you go. Drop it down a burrow, or take it home with you and bin it. Leaving out food, especially in an exposed spot, might mean the voles get predated, or it might encourage rats. In fact if you're feeding any wild animal, always clear up the excess.