Potatoes being eaten

What came into my garden last night and dug up quite a few of my main crop potatoes, leaving nibbled oval holes about 1- 2 cm across and 1 cm deep. I garden in the countryside next to a meadow.  No other veg seem to have been eaten this time although earlier in the year 3 or 4 beetroot were uprooted and similarly nibbled.  Obviously likes root vegetables.  Fences all seem to be intact. Any ideas?  I am thinking rats?  Not enough damage for badgers I don't think.