Little dormouse?

A late night last night playing samba and eating different dishes from around the world. We were a very cosmopolitan group, and each person had at make a dish from their country. We made (vegetarian!) cottage pie and Eton Mess. Other offerings included bacon and cabbage (Irish) and a rather amazing peanut butter and nutella pie (American, 1 million calories).
A long walk was necessary. We did a bit of the Sheeps Head Way, and en route spotted this little creature. It was totally unafraid and too busy eating its bit of barely/rye to worry about us. Is it a dormouse?? A field mouse? It was tiny.